

<!--Generated by Disclosure Solutions PROFILE 2.6.2.0 Copyright 1995 - 2013 Thomson Reuters Accelus. All rights reserved.-->
<link:linkbase xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:t1="http://xbrl.org/2005/xbrldt">
  <link:roleRef roleURI="http://belfuse.com/role/SubsequentEventsDetails" xlink:type="simple" xlink:href="belfb-20140630.xsd#SubsequentEventsDetails" />
  <link:roleRef roleURI="http://belfuse.com/role/CommitmentsAndContingenciesDetails" xlink:type="simple" xlink:href="belfb-20140630.xsd#CommitmentsAndContingenciesDetails" />
  <link:roleRef roleURI="http://belfuse.com/role/AccumulatedOtherComprehensiveIncomeDetails" xlink:type="simple" xlink:href="belfb-20140630.xsd#AccumulatedOtherComprehensiveIncomeDetails" />
  <link:roleRef roleURI="http://belfuse.com/role/RetirementFundAndProfitSharingPlanDetails" xlink:type="simple" xlink:href="belfb-20140630.xsd#RetirementFundAndProfitSharingPlanDetails" />
  <link:roleRef roleURI="http://belfuse.com/role/DebtDetailsCalc2" xlink:type="simple" xlink:href="belfb-20140630.xsd#DebtDetailsCalc2" />
  <link:roleRef roleURI="http://belfuse.com/role/DebtDetails" xlink:type="simple" xlink:href="belfb-20140630.xsd#DebtDetails" />
  <link:roleRef roleURI="http://belfuse.com/role/AccruedExpensesDetails" xlink:type="simple" xlink:href="belfb-20140630.xsd#AccruedExpensesDetails" />
  <link:roleRef roleURI="http://belfuse.com/role/IncomeTaxesDetails" xlink:type="simple" xlink:href="belfb-20140630.xsd#IncomeTaxesDetails" />
  <link:roleRef roleURI="http://belfuse.com/role/BusinessSegmentInformationDetails" xlink:type="simple" xlink:href="belfb-20140630.xsd#BusinessSegmentInformationDetails" />
  <link:roleRef roleURI="http://belfuse.com/role/PropertyPlantAndEquipmentDetails" xlink:type="simple" xlink:href="belfb-20140630.xsd#PropertyPlantAndEquipmentDetails" />
  <link:roleRef roleURI="http://belfuse.com/role/InventoriesDetails" xlink:type="simple" xlink:href="belfb-20140630.xsd#InventoriesDetails" />
  <link:roleRef roleURI="http://belfuse.com/role/FairValueMeasurementsDetails" xlink:type="simple" xlink:href="belfb-20140630.xsd#FairValueMeasurementsDetails" />
  <link:roleRef roleURI="http://belfuse.com/role/AcquisitionsDetails" xlink:type="simple" xlink:href="belfb-20140630.xsd#AcquisitionsDetails" />
  <link:roleRef roleURI="http://belfuse.com/role/EarningsPerShareDetails" xlink:type="simple" xlink:href="belfb-20140630.xsd#EarningsPerShareDetails" />
  <link:roleRef roleURI="http://belfuse.com/role/BasisOfPresentationAndAccountingPoliciesDetails" xlink:type="simple" xlink:href="belfb-20140630.xsd#BasisOfPresentationAndAccountingPoliciesDetails" />
  <link:roleRef roleURI="http://belfuse.com/role/AccumulatedOtherComprehensiveIncomeTables" xlink:type="simple" xlink:href="belfb-20140630.xsd#AccumulatedOtherComprehensiveIncomeTables" />
  <link:roleRef roleURI="http://belfuse.com/role/RetirementFundAndProfitSharingPlanTables" xlink:type="simple" xlink:href="belfb-20140630.xsd#RetirementFundAndProfitSharingPlanTables" />
  <link:roleRef roleURI="http://belfuse.com/role/DebtTables" xlink:type="simple" xlink:href="belfb-20140630.xsd#DebtTables" />
  <link:roleRef roleURI="http://belfuse.com/role/AccruedExpensesTables" xlink:type="simple" xlink:href="belfb-20140630.xsd#AccruedExpensesTables" />
  <link:roleRef roleURI="http://belfuse.com/role/BusinessSegmentInformationTables" xlink:type="simple" xlink:href="belfb-20140630.xsd#BusinessSegmentInformationTables" />
  <link:roleRef roleURI="http://belfuse.com/role/PropertyPlantAndEquipmentTables" xlink:type="simple" xlink:href="belfb-20140630.xsd#PropertyPlantAndEquipmentTables" />
  <link:roleRef roleURI="http://belfuse.com/role/InventoriesTables" xlink:type="simple" xlink:href="belfb-20140630.xsd#InventoriesTables" />
  <link:roleRef roleURI="http://belfuse.com/role/FairValueMeasurementsTables" xlink:type="simple" xlink:href="belfb-20140630.xsd#FairValueMeasurementsTables" />
  <link:roleRef roleURI="http://belfuse.com/role/AcquisitionsTables" xlink:type="simple" xlink:href="belfb-20140630.xsd#AcquisitionsTables" />
  <link:roleRef roleURI="http://belfuse.com/role/EarningsPerShareTables" xlink:type="simple" xlink:href="belfb-20140630.xsd#EarningsPerShareTables" />
  <link:roleRef roleURI="http://belfuse.com/role/BasisOfPresentationAndAccountingPoliciesPolicies" xlink:type="simple" xlink:href="belfb-20140630.xsd#BasisOfPresentationAndAccountingPoliciesPolicies" />
  <link:roleRef roleURI="http://belfuse.com/role/SubsequentEvents" xlink:type="simple" xlink:href="belfb-20140630.xsd#SubsequentEvents" />
  <link:roleRef roleURI="http://belfuse.com/role/CommitmentsAndContingencies" xlink:type="simple" xlink:href="belfb-20140630.xsd#CommitmentsAndContingencies" />
  <link:roleRef roleURI="http://belfuse.com/role/AccumulatedOtherComprehensiveIncome" xlink:type="simple" xlink:href="belfb-20140630.xsd#AccumulatedOtherComprehensiveIncome" />
  <link:roleRef roleURI="http://belfuse.com/role/RetirementFundAndProfitSharingPlan" xlink:type="simple" xlink:href="belfb-20140630.xsd#RetirementFundAndProfitSharingPlan" />
  <link:roleRef roleURI="http://belfuse.com/role/Debt" xlink:type="simple" xlink:href="belfb-20140630.xsd#Debt" />
  <link:roleRef roleURI="http://belfuse.com/role/AccruedExpenses" xlink:type="simple" xlink:href="belfb-20140630.xsd#AccruedExpenses" />
  <link:roleRef roleURI="http://belfuse.com/role/IncomeTaxes" xlink:type="simple" xlink:href="belfb-20140630.xsd#IncomeTaxes" />
  <link:roleRef roleURI="http://belfuse.com/role/BusinessSegmentInformation" xlink:type="simple" xlink:href="belfb-20140630.xsd#BusinessSegmentInformation" />
  <link:roleRef roleURI="http://belfuse.com/role/PropertyPlantAndEquipment" xlink:type="simple" xlink:href="belfb-20140630.xsd#PropertyPlantAndEquipment" />
  <link:roleRef roleURI="http://belfuse.com/role/Inventories" xlink:type="simple" xlink:href="belfb-20140630.xsd#Inventories" />
  <link:roleRef roleURI="http://belfuse.com/role/FairValueMeasurements" xlink:type="simple" xlink:href="belfb-20140630.xsd#FairValueMeasurements" />
  <link:roleRef roleURI="http://belfuse.com/role/Acquisitions" xlink:type="simple" xlink:href="belfb-20140630.xsd#Acquisitions" />
  <link:roleRef roleURI="http://belfuse.com/role/EarningsPerShare" xlink:type="simple" xlink:href="belfb-20140630.xsd#EarningsPerShare" />
  <link:roleRef roleURI="http://belfuse.com/role/BasisOfPresentationAndAccountingPolicies" xlink:type="simple" xlink:href="belfb-20140630.xsd#BasisOfPresentationAndAccountingPolicies" />
  <link:roleRef roleURI="http://belfuse.com/role/CondensedConsolidatedStatementsOfCashFlowsUnaudited" xlink:type="simple" xlink:href="belfb-20140630.xsd#CondensedConsolidatedStatementsOfCashFlowsUnaudited" />
  <link:roleRef roleURI="http://belfuse.com/role/CondensedConsolidatedStatementsOfComprehensiveIncomeLossUnauditedParenthetical" xlink:type="simple" xlink:href="belfb-20140630.xsd#CondensedConsolidatedStatementsOfComprehensiveIncomeLossUnauditedParenthetical" />
  <link:roleRef roleURI="http://belfuse.com/role/CondensedConsolidatedStatementsOfComprehensiveIncomeLossUnaudited" xlink:type="simple" xlink:href="belfb-20140630.xsd#CondensedConsolidatedStatementsOfComprehensiveIncomeLossUnaudited" />
  <link:roleRef roleURI="http://belfuse.com/role/CondensedConsolidatedStatementsOfOperationsUnaudited" xlink:type="simple" xlink:href="belfb-20140630.xsd#CondensedConsolidatedStatementsOfOperationsUnaudited" />
  <link:roleRef roleURI="http://belfuse.com/role/CondensedConsolidatedBalanceSheetsUnauditedParenthetical" xlink:type="simple" xlink:href="belfb-20140630.xsd#CondensedConsolidatedBalanceSheetsUnauditedParenthetical" />
  <link:roleRef roleURI="http://belfuse.com/role/CondensedConsolidatedBalanceSheetsUnaudited" xlink:type="simple" xlink:href="belfb-20140630.xsd#CondensedConsolidatedBalanceSheetsUnaudited" />
  <link:roleRef roleURI="http://belfuse.com/role/DocumentAndEntityInformation" xlink:type="simple" xlink:href="belfb-20140630.xsd#DocumentAndEntityInformation" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/DocumentAndEntityInformation">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityInformationLineItems" xlink:label="EntityInformationLineItems" xlink:title="EntityInformationLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityRegistrantName" xlink:label="EntityRegistrantName" xlink:title="EntityRegistrantName" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EntityInformationLineItems" xlink:to="EntityRegistrantName" xlink:title="definition: EntityInformationLineItems to EntityRegistrantName" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCentralIndexKey" xlink:label="EntityCentralIndexKey" xlink:title="EntityCentralIndexKey" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EntityInformationLineItems" xlink:to="EntityCentralIndexKey" xlink:title="definition: EntityInformationLineItems to EntityCentralIndexKey" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:label="CurrentFiscalYearEndDate" xlink:title="CurrentFiscalYearEndDate" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EntityInformationLineItems" xlink:to="CurrentFiscalYearEndDate" xlink:title="definition: EntityInformationLineItems to CurrentFiscalYearEndDate" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityWellKnownSeasonedIssuer" xlink:label="EntityWellKnownSeasonedIssuer" xlink:title="EntityWellKnownSeasonedIssuer" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EntityInformationLineItems" xlink:to="EntityWellKnownSeasonedIssuer" xlink:title="definition: EntityInformationLineItems to EntityWellKnownSeasonedIssuer" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityVoluntaryFilers" xlink:label="EntityVoluntaryFilers" xlink:title="EntityVoluntaryFilers" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EntityInformationLineItems" xlink:to="EntityVoluntaryFilers" xlink:title="definition: EntityInformationLineItems to EntityVoluntaryFilers" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCurrentReportingStatus" xlink:label="EntityCurrentReportingStatus" xlink:title="EntityCurrentReportingStatus" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EntityInformationLineItems" xlink:to="EntityCurrentReportingStatus" xlink:title="definition: EntityInformationLineItems to EntityCurrentReportingStatus" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityFilerCategory" xlink:label="EntityFilerCategory" xlink:title="EntityFilerCategory" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EntityInformationLineItems" xlink:to="EntityFilerCategory" xlink:title="definition: EntityInformationLineItems to EntityFilerCategory" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityPublicFloat" xlink:label="EntityPublicFloat" xlink:title="EntityPublicFloat" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EntityInformationLineItems" xlink:to="EntityPublicFloat" xlink:title="definition: EntityInformationLineItems to EntityPublicFloat" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="EntityCommonStockSharesOutstanding" xlink:title="EntityCommonStockSharesOutstanding" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EntityInformationLineItems" xlink:to="EntityCommonStockSharesOutstanding" xlink:title="definition: EntityInformationLineItems to EntityCommonStockSharesOutstanding" order="9.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:label="DocumentFiscalYearFocus" xlink:title="DocumentFiscalYearFocus" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EntityInformationLineItems" xlink:to="DocumentFiscalYearFocus" xlink:title="definition: EntityInformationLineItems to DocumentFiscalYearFocus" order="10.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="DocumentFiscalPeriodFocus" xlink:title="DocumentFiscalPeriodFocus" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EntityInformationLineItems" xlink:to="DocumentFiscalPeriodFocus" xlink:title="definition: EntityInformationLineItems to DocumentFiscalPeriodFocus" order="11.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentType" xlink:label="DocumentType" xlink:title="DocumentType" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EntityInformationLineItems" xlink:to="DocumentType" xlink:title="definition: EntityInformationLineItems to DocumentType" order="12.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_AmendmentFlag" xlink:label="AmendmentFlag" xlink:title="AmendmentFlag" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EntityInformationLineItems" xlink:to="AmendmentFlag" xlink:title="definition: EntityInformationLineItems to AmendmentFlag" order="13.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentPeriodEndDate" xlink:label="DocumentPeriodEndDate" xlink:title="DocumentPeriodEndDate" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EntityInformationLineItems" xlink:to="DocumentPeriodEndDate" xlink:title="definition: EntityInformationLineItems to DocumentPeriodEndDate" order="14.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntitiesTable" xlink:label="EntitiesTable" xlink:title="EntitiesTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="EntityInformationLineItems" xlink:to="EntitiesTable" xlink:title="definition: EntityInformationLineItems to EntitiesTable" order="15.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="StatementClassOfStockAxis" xlink:title="StatementClassOfStockAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="EntitiesTable" xlink:to="StatementClassOfStockAxis" xlink:title="definition: EntitiesTable to StatementClassOfStockAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain_2" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain_2" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="CommonClassAMember" xlink:title="CommonClassAMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="CommonClassAMember" xlink:title="definition: ClassOfStockDomain to CommonClassAMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="CommonClassBMember" xlink:title="CommonClassBMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="CommonClassBMember" xlink:title="definition: ClassOfStockDomain to CommonClassBMember" order="2.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/CondensedConsolidatedBalanceSheetsUnaudited">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementLineItems" xlink:label="StatementLineItems" xlink:title="StatementLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="AssetsAbstract" xlink:title="AssetsAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="AssetsAbstract" xlink:title="definition: StatementLineItems to AssetsAbstract" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="LiabilitiesAndStockholdersEquityAbstract" xlink:title="LiabilitiesAndStockholdersEquityAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="LiabilitiesAndStockholdersEquityAbstract" xlink:title="definition: StatementLineItems to LiabilitiesAndStockholdersEquityAbstract" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="LiabilitiesCurrentAbstract" xlink:title="LiabilitiesCurrentAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="LiabilitiesCurrentAbstract" xlink:title="definition: StatementLineItems to LiabilitiesCurrentAbstract" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesNoncurrentAbstract" xlink:label="LiabilitiesNoncurrentAbstract" xlink:title="LiabilitiesNoncurrentAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="LiabilitiesNoncurrentAbstract" xlink:title="definition: StatementLineItems to LiabilitiesNoncurrentAbstract" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="CommitmentsAndContingencies" xlink:title="CommitmentsAndContingencies" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="CommitmentsAndContingencies" xlink:title="definition: StatementLineItems to CommitmentsAndContingencies" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="StockholdersEquityAbstract" xlink:title="StockholdersEquityAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="StockholdersEquityAbstract" xlink:title="definition: StatementLineItems to StockholdersEquityAbstract" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="PreferredStockValue" xlink:title="PreferredStockValue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="PreferredStockValue" xlink:title="definition: StatementLineItems to PreferredStockValue" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockValue" xlink:label="CommonStockValue" xlink:title="CommonStockValue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="CommonStockValue" xlink:title="definition: StatementLineItems to CommonStockValue" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:label="AdditionalPaidInCapitalCommonStock" xlink:title="AdditionalPaidInCapitalCommonStock" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="AdditionalPaidInCapitalCommonStock" xlink:title="definition: StatementLineItems to AdditionalPaidInCapitalCommonStock" order="9.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="RetainedEarningsAccumulatedDeficit" xlink:title="RetainedEarningsAccumulatedDeficit" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="RetainedEarningsAccumulatedDeficit" xlink:title="definition: StatementLineItems to RetainedEarningsAccumulatedDeficit" order="10.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:title="AccumulatedOtherComprehensiveIncomeLossNetOfTax" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:title="definition: StatementLineItems to AccumulatedOtherComprehensiveIncomeLossNetOfTax" order="11.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="StockholdersEquity" xlink:title="StockholdersEquity" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="StockholdersEquity" xlink:title="definition: StatementLineItems to StockholdersEquity" order="12.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="LiabilitiesAndStockholdersEquity" xlink:title="LiabilitiesAndStockholdersEquity" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="LiabilitiesAndStockholdersEquity" xlink:title="definition: StatementLineItems to LiabilitiesAndStockholdersEquity" order="13.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="LongTermDebtNoncurrent" xlink:title="LongTermDebtNoncurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="LongTermDebtNoncurrent" xlink:title="definition: StatementLineItems to LongTermDebtNoncurrent" order="14.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilityForUncertainTaxPositionsNoncurrent" xlink:label="LiabilityForUncertainTaxPositionsNoncurrent" xlink:title="LiabilityForUncertainTaxPositionsNoncurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="LiabilityForUncertainTaxPositionsNoncurrent" xlink:title="definition: StatementLineItems to LiabilityForUncertainTaxPositionsNoncurrent" order="15.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:label="PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:title="PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:title="definition: StatementLineItems to PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" order="16.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="OtherLiabilitiesNoncurrent" xlink:title="OtherLiabilitiesNoncurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="OtherLiabilitiesNoncurrent" xlink:title="definition: StatementLineItems to OtherLiabilitiesNoncurrent" order="17.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesNoncurrent" xlink:label="LiabilitiesNoncurrent" xlink:title="LiabilitiesNoncurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="LiabilitiesNoncurrent" xlink:title="definition: StatementLineItems to LiabilitiesNoncurrent" order="18.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_Liabilities" xlink:label="Liabilities" xlink:title="Liabilities" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="Liabilities" xlink:title="definition: StatementLineItems to Liabilities" order="19.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="AccountsPayableCurrent" xlink:title="AccountsPayableCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="AccountsPayableCurrent" xlink:title="definition: StatementLineItems to AccountsPayableCurrent" order="20.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="AccruedLiabilitiesCurrent" xlink:title="AccruedLiabilitiesCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="AccruedLiabilitiesCurrent" xlink:title="definition: StatementLineItems to AccruedLiabilitiesCurrent" order="21.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LinesOfCreditCurrent" xlink:label="LinesOfCreditCurrent" xlink:title="LinesOfCreditCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="LinesOfCreditCurrent" xlink:title="definition: StatementLineItems to LinesOfCreditCurrent" order="22.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebtCurrent" xlink:label="LongTermDebtCurrent" xlink:title="LongTermDebtCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="LongTermDebtCurrent" xlink:title="definition: StatementLineItems to LongTermDebtCurrent" order="23.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NotesPayableCurrent" xlink:label="NotesPayableCurrent" xlink:title="NotesPayableCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="NotesPayableCurrent" xlink:title="definition: StatementLineItems to NotesPayableCurrent" order="24.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccruedIncomeTaxesCurrent" xlink:label="AccruedIncomeTaxesCurrent" xlink:title="AccruedIncomeTaxesCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="AccruedIncomeTaxesCurrent" xlink:title="definition: StatementLineItems to AccruedIncomeTaxesCurrent" order="25.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DividendsPayableCurrent" xlink:label="DividendsPayableCurrent" xlink:title="DividendsPayableCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="DividendsPayableCurrent" xlink:title="definition: StatementLineItems to DividendsPayableCurrent" order="26.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="LiabilitiesCurrent" xlink:title="LiabilitiesCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="LiabilitiesCurrent" xlink:title="definition: StatementLineItems to LiabilitiesCurrent" order="27.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="AssetsCurrentAbstract" xlink:title="AssetsCurrentAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="AssetsCurrentAbstract" xlink:title="definition: StatementLineItems to AssetsCurrentAbstract" order="28.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="PropertyPlantAndEquipmentNet" xlink:title="PropertyPlantAndEquipmentNet" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="PropertyPlantAndEquipmentNet" xlink:title="definition: StatementLineItems to PropertyPlantAndEquipmentNet" order="29.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DeferredTaxAssetsNetNoncurrent" xlink:label="DeferredTaxAssetsNetNoncurrent" xlink:title="DeferredTaxAssetsNetNoncurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="DeferredTaxAssetsNetNoncurrent" xlink:title="definition: StatementLineItems to DeferredTaxAssetsNetNoncurrent" order="30.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="IntangibleAssetsNetExcludingGoodwill" xlink:title="IntangibleAssetsNetExcludingGoodwill" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="IntangibleAssetsNetExcludingGoodwill" xlink:title="definition: StatementLineItems to IntangibleAssetsNetExcludingGoodwill" order="31.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_Goodwill" xlink:label="Goodwill" xlink:title="Goodwill" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="Goodwill" xlink:title="definition: StatementLineItems to Goodwill" order="32.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="OtherAssetsNoncurrent" xlink:title="OtherAssetsNoncurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="OtherAssetsNoncurrent" xlink:title="definition: StatementLineItems to OtherAssetsNoncurrent" order="33.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_Assets" xlink:label="Assets" xlink:title="Assets" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="Assets" xlink:title="definition: StatementLineItems to Assets" order="34.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="CashAndCashEquivalentsAtCarryingValue" xlink:title="CashAndCashEquivalentsAtCarryingValue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="CashAndCashEquivalentsAtCarryingValue" xlink:title="definition: StatementLineItems to CashAndCashEquivalentsAtCarryingValue" order="35.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="AccountsReceivableNetCurrent" xlink:title="AccountsReceivableNetCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="AccountsReceivableNetCurrent" xlink:title="definition: StatementLineItems to AccountsReceivableNetCurrent" order="36.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InventoryNet" xlink:label="InventoryNet" xlink:title="InventoryNet" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="InventoryNet" xlink:title="definition: StatementLineItems to InventoryNet" order="37.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="PrepaidExpenseAndOtherAssetsCurrent" xlink:title="PrepaidExpenseAndOtherAssetsCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="PrepaidExpenseAndOtherAssetsCurrent" xlink:title="definition: StatementLineItems to PrepaidExpenseAndOtherAssetsCurrent" order="38.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeTaxesReceivable" xlink:label="IncomeTaxesReceivable" xlink:title="IncomeTaxesReceivable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="IncomeTaxesReceivable" xlink:title="definition: StatementLineItems to IncomeTaxesReceivable" order="39.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DeferredTaxAssetsNetCurrent" xlink:label="DeferredTaxAssetsNetCurrent" xlink:title="DeferredTaxAssetsNetCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="DeferredTaxAssetsNetCurrent" xlink:title="definition: StatementLineItems to DeferredTaxAssetsNetCurrent" order="40.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="AssetsCurrent" xlink:title="AssetsCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="AssetsCurrent" xlink:title="definition: StatementLineItems to AssetsCurrent" order="41.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementTable" xlink:label="StatementTable" xlink:title="StatementTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="StatementLineItems" xlink:to="StatementTable" xlink:title="definition: StatementLineItems to StatementTable" order="42.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="StatementClassOfStockAxis" xlink:title="StatementClassOfStockAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="StatementTable" xlink:to="StatementClassOfStockAxis" xlink:title="definition: StatementTable to StatementClassOfStockAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain_2" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain_2" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="CommonClassAMember" xlink:title="CommonClassAMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="CommonClassAMember" xlink:title="definition: ClassOfStockDomain to CommonClassAMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="CommonClassBMember" xlink:title="CommonClassBMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="CommonClassBMember" xlink:title="definition: ClassOfStockDomain to CommonClassBMember" order="2.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/CondensedConsolidatedBalanceSheetsUnauditedParenthetical">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementLineItems" xlink:label="StatementLineItems" xlink:title="StatementLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="AssetsAbstract" xlink:title="AssetsAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="AssetsAbstract" xlink:title="definition: StatementLineItems to AssetsAbstract" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="LiabilitiesAndStockholdersEquityAbstract" xlink:title="LiabilitiesAndStockholdersEquityAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="LiabilitiesAndStockholdersEquityAbstract" xlink:title="definition: StatementLineItems to LiabilitiesAndStockholdersEquityAbstract" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="StockholdersEquityAbstract" xlink:title="StockholdersEquityAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="StockholdersEquityAbstract" xlink:title="definition: StatementLineItems to StockholdersEquityAbstract" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockNoParValue" xlink:label="PreferredStockNoParValue" xlink:title="PreferredStockNoParValue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="PreferredStockNoParValue" xlink:title="definition: StatementLineItems to PreferredStockNoParValue" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="PreferredStockSharesAuthorized" xlink:title="PreferredStockSharesAuthorized" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="PreferredStockSharesAuthorized" xlink:title="definition: StatementLineItems to PreferredStockSharesAuthorized" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="PreferredStockSharesIssued" xlink:title="PreferredStockSharesIssued" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="PreferredStockSharesIssued" xlink:title="definition: StatementLineItems to PreferredStockSharesIssued" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="CommonStockParOrStatedValuePerShare" xlink:title="CommonStockParOrStatedValuePerShare" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="CommonStockParOrStatedValuePerShare" xlink:title="definition: StatementLineItems to CommonStockParOrStatedValuePerShare" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="CommonStockSharesAuthorized" xlink:title="CommonStockSharesAuthorized" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="CommonStockSharesAuthorized" xlink:title="definition: StatementLineItems to CommonStockSharesAuthorized" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="CommonStockSharesOutstanding" xlink:title="CommonStockSharesOutstanding" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="CommonStockSharesOutstanding" xlink:title="definition: StatementLineItems to CommonStockSharesOutstanding" order="9.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_TreasuryStockShares" xlink:label="TreasuryStockShares" xlink:title="TreasuryStockShares" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="TreasuryStockShares" xlink:title="definition: StatementLineItems to TreasuryStockShares" order="10.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="AssetsCurrentAbstract" xlink:title="AssetsCurrentAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="AssetsCurrentAbstract" xlink:title="definition: StatementLineItems to AssetsCurrentAbstract" order="11.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:label="AllowanceForDoubtfulAccountsReceivableCurrent" xlink:title="AllowanceForDoubtfulAccountsReceivableCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="AllowanceForDoubtfulAccountsReceivableCurrent" xlink:title="definition: StatementLineItems to AllowanceForDoubtfulAccountsReceivableCurrent" order="12.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementTable" xlink:label="StatementTable" xlink:title="StatementTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="StatementLineItems" xlink:to="StatementTable" xlink:title="definition: StatementLineItems to StatementTable" order="13.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="StatementClassOfStockAxis" xlink:title="StatementClassOfStockAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="StatementTable" xlink:to="StatementClassOfStockAxis" xlink:title="definition: StatementTable to StatementClassOfStockAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain_2" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain_2" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="CommonClassAMember" xlink:title="CommonClassAMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="CommonClassAMember" xlink:title="definition: ClassOfStockDomain to CommonClassAMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="CommonClassBMember" xlink:title="CommonClassBMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="CommonClassBMember" xlink:title="definition: ClassOfStockDomain to CommonClassBMember" order="2.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/CondensedConsolidatedStatementsOfOperationsUnaudited">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementLineItems" xlink:label="StatementLineItems" xlink:title="StatementLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SalesRevenueGoodsNet" xlink:label="SalesRevenueGoodsNet" xlink:title="SalesRevenueGoodsNet" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="SalesRevenueGoodsNet" xlink:title="definition: StatementLineItems to SalesRevenueGoodsNet" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingCostsAndExpensesAbstract" xlink:label="OperatingCostsAndExpensesAbstract" xlink:title="OperatingCostsAndExpensesAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="OperatingCostsAndExpensesAbstract" xlink:title="definition: StatementLineItems to OperatingCostsAndExpensesAbstract" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="OperatingIncomeLoss" xlink:title="OperatingIncomeLoss" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="OperatingIncomeLoss" xlink:title="definition: StatementLineItems to OperatingIncomeLoss" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InterestExpense" xlink:label="InterestExpense" xlink:title="InterestExpense" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="InterestExpense" xlink:title="definition: StatementLineItems to InterestExpense" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherNonoperatingIncome" xlink:label="OtherNonoperatingIncome" xlink:title="OtherNonoperatingIncome" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="OtherNonoperatingIncome" xlink:title="definition: StatementLineItems to OtherNonoperatingIncome" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:title="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:title="definition: StatementLineItems to IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="IncomeTaxExpenseBenefit" xlink:title="IncomeTaxExpenseBenefit" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="IncomeTaxExpenseBenefit" xlink:title="definition: StatementLineItems to IncomeTaxExpenseBenefit" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="NetIncomeLoss" xlink:title="NetIncomeLoss" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="NetIncomeLoss" xlink:title="definition: StatementLineItems to NetIncomeLoss" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="EarningsPerShareAbstract" xlink:title="EarningsPerShareAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="EarningsPerShareAbstract" xlink:title="definition: StatementLineItems to EarningsPerShareAbstract" order="9.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:label="WeightedAverageNumberOfSharesOutstandingAbstract" xlink:title="WeightedAverageNumberOfSharesOutstandingAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="WeightedAverageNumberOfSharesOutstandingAbstract" xlink:title="definition: StatementLineItems to WeightedAverageNumberOfSharesOutstandingAbstract" order="10.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_DividendsPaidPerShareAbstract" xlink:label="DividendsPaidPerShareAbstract" xlink:title="DividendsPaidPerShareAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="DividendsPaidPerShareAbstract" xlink:title="definition: StatementLineItems to DividendsPaidPerShareAbstract" order="11.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockDividendsPerShareCashPaid" xlink:label="CommonStockDividendsPerShareCashPaid" xlink:title="CommonStockDividendsPerShareCashPaid" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="CommonStockDividendsPerShareCashPaid" xlink:title="definition: StatementLineItems to CommonStockDividendsPerShareCashPaid" order="12.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:label="WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:title="WeightedAverageNumberOfShareOutstandingBasicAndDiluted" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:title="definition: StatementLineItems to WeightedAverageNumberOfShareOutstandingBasicAndDiluted" order="13.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EarningsPerShareBasicAndDiluted" xlink:label="EarningsPerShareBasicAndDiluted" xlink:title="EarningsPerShareBasicAndDiluted" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="EarningsPerShareBasicAndDiluted" xlink:title="definition: StatementLineItems to EarningsPerShareBasicAndDiluted" order="14.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CostOfGoodsSold" xlink:label="CostOfGoodsSold" xlink:title="CostOfGoodsSold" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="CostOfGoodsSold" xlink:title="definition: StatementLineItems to CostOfGoodsSold" order="15.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="SellingGeneralAndAdministrativeExpense" xlink:title="SellingGeneralAndAdministrativeExpense" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="SellingGeneralAndAdministrativeExpense" xlink:title="definition: StatementLineItems to SellingGeneralAndAdministrativeExpense" order="16.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RestructuringCharges" xlink:label="RestructuringCharges" xlink:title="RestructuringCharges" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="RestructuringCharges" xlink:title="definition: StatementLineItems to RestructuringCharges" order="17.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CostsAndExpenses" xlink:label="CostsAndExpenses" xlink:title="CostsAndExpenses" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="CostsAndExpenses" xlink:title="definition: StatementLineItems to CostsAndExpenses" order="18.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementTable" xlink:label="StatementTable" xlink:title="StatementTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="StatementLineItems" xlink:to="StatementTable" xlink:title="definition: StatementLineItems to StatementTable" order="19.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="StatementClassOfStockAxis" xlink:title="StatementClassOfStockAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="StatementTable" xlink:to="StatementClassOfStockAxis" xlink:title="definition: StatementTable to StatementClassOfStockAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain_2" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain_2" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="CommonClassAMember" xlink:title="CommonClassAMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="CommonClassAMember" xlink:title="definition: ClassOfStockDomain to CommonClassAMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="CommonClassBMember" xlink:title="CommonClassBMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="CommonClassBMember" xlink:title="definition: ClassOfStockDomain to CommonClassBMember" order="2.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/CondensedConsolidatedStatementsOfComprehensiveIncomeLossUnaudited" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/CondensedConsolidatedStatementsOfComprehensiveIncomeLossUnauditedParenthetical" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/CondensedConsolidatedStatementsOfCashFlowsUnaudited" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/BasisOfPresentationAndAccountingPolicies" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/EarningsPerShare" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/Acquisitions" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/FairValueMeasurements" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/Inventories" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/PropertyPlantAndEquipment" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/BusinessSegmentInformation" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/IncomeTaxes" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/AccruedExpenses" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/Debt" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/RetirementFundAndProfitSharingPlan" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/AccumulatedOtherComprehensiveIncome" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/CommitmentsAndContingencies" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/SubsequentEvents" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/BasisOfPresentationAndAccountingPoliciesPolicies" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/EarningsPerShareTables" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/AcquisitionsTables">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="BusinessAcquisitionLineItems" xlink:title="BusinessAcquisitionLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:label="ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:title="ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:title="definition: BusinessAcquisitionLineItems to ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionProFormaInformationTextBlock" xlink:label="BusinessAcquisitionProFormaInformationTextBlock" xlink:title="BusinessAcquisitionProFormaInformationTextBlock" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessAcquisitionProFormaInformationTextBlock" xlink:title="definition: BusinessAcquisitionLineItems to BusinessAcquisitionProFormaInformationTextBlock" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:title="ScheduleOfBusinessAcquisitionsByAcquisitionTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="BusinessAcquisitionLineItems" xlink:to="ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:title="definition: BusinessAcquisitionLineItems to ScheduleOfBusinessAcquisitionsByAcquisitionTable" order="3.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="BusinessAcquisitionAxis" xlink:title="BusinessAcquisitionAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="BusinessAcquisitionAxis" xlink:title="definition: ScheduleOfBusinessAcquisitionsByAcquisitionTable to BusinessAcquisitionAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="BusinessAcquisitionAcquireeDomain" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="BusinessAcquisitionAxis" xlink:to="BusinessAcquisitionAcquireeDomain" xlink:title="definition: BusinessAcquisitionAxis to BusinessAcquisitionAcquireeDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="BusinessAcquisitionAcquireeDomain_2" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="BusinessAcquisitionAxis" xlink:to="BusinessAcquisitionAcquireeDomain_2" xlink:title="definition: BusinessAcquisitionAxis to BusinessAcquisitionAcquireeDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_PowerSolutionsMember" xlink:label="PowerSolutionsMember" xlink:title="PowerSolutionsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="PowerSolutionsMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to PowerSolutionsMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_TrpAndArrayMember" xlink:label="TrpAndArrayMember" xlink:title="TrpAndArrayMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="TrpAndArrayMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to TrpAndArrayMember" order="2.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/FairValueMeasurementsTables" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/InventoriesTables" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/PropertyPlantAndEquipmentTables" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/BusinessSegmentInformationTables" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/AccruedExpensesTables" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/DebtTables" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/RetirementFundAndProfitSharingPlanTables" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/AccumulatedOtherComprehensiveIncomeTables" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/BasisOfPresentationAndAccountingPoliciesDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="BusinessAcquisitionLineItems" xlink:title="BusinessAcquisitionLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionEffectiveDateOfAcquisition1" xlink:label="BusinessAcquisitionEffectiveDateOfAcquisition1" xlink:title="BusinessAcquisitionEffectiveDateOfAcquisition1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessAcquisitionEffectiveDateOfAcquisition1" xlink:title="definition: BusinessAcquisitionLineItems to BusinessAcquisitionEffectiveDateOfAcquisition1" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:label="BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:title="BusinessAcquisitionPercentageOfVotingInterestsAcquired" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:title="definition: BusinessAcquisitionLineItems to BusinessAcquisitionPercentageOfVotingInterestsAcquired" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:title="ScheduleOfBusinessAcquisitionsByAcquisitionTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="BusinessAcquisitionLineItems" xlink:to="ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:title="definition: BusinessAcquisitionLineItems to ScheduleOfBusinessAcquisitionsByAcquisitionTable" order="3.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="BusinessAcquisitionAxis" xlink:title="BusinessAcquisitionAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="BusinessAcquisitionAxis" xlink:title="definition: ScheduleOfBusinessAcquisitionsByAcquisitionTable to BusinessAcquisitionAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="BusinessAcquisitionAcquireeDomain" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="BusinessAcquisitionAxis" xlink:to="BusinessAcquisitionAcquireeDomain" xlink:title="definition: BusinessAcquisitionAxis to BusinessAcquisitionAcquireeDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="BusinessAcquisitionAcquireeDomain_2" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="BusinessAcquisitionAxis" xlink:to="BusinessAcquisitionAcquireeDomain_2" xlink:title="definition: BusinessAcquisitionAxis to BusinessAcquisitionAcquireeDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_GigacomInterconnectMember" xlink:label="GigacomInterconnectMember" xlink:title="GigacomInterconnectMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="GigacomInterconnectMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to GigacomInterconnectMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_PowerboxItalyMember" xlink:label="PowerboxItalyMember" xlink:title="PowerboxItalyMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="PowerboxItalyMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to PowerboxItalyMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_FibrecoMember" xlink:label="FibrecoMember" xlink:title="FibrecoMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="FibrecoMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to FibrecoMember" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_TrpMember" xlink:label="TrpMember" xlink:title="TrpMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="TrpMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to TrpMember" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_ArrayMember" xlink:label="ArrayMember" xlink:title="ArrayMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="ArrayMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to ArrayMember" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_PowerSolutionsMember" xlink:label="PowerSolutionsMember" xlink:title="PowerSolutionsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="PowerSolutionsMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to PowerSolutionsMember" order="6.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/EarningsPerShareDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EarningsPerShareDilutedLineItems" xlink:label="EarningsPerShareDilutedLineItems" xlink:title="EarningsPerShareDilutedLineItems" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_ExcessiveDividendRateOfOneClassOverOtherClass" xlink:label="ExcessiveDividendRateOfOneClassOverOtherClass" xlink:title="ExcessiveDividendRateOfOneClassOverOtherClass" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EarningsPerShareDilutedLineItems" xlink:to="ExcessiveDividendRateOfOneClassOverOtherClass" xlink:title="definition: EarningsPerShareDilutedLineItems to ExcessiveDividendRateOfOneClassOverOtherClass" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_ExcessiveUndistributedEarningsAllocationRateOfOneClassOverOtherClass" xlink:label="ExcessiveUndistributedEarningsAllocationRateOfOneClassOverOtherClass" xlink:title="ExcessiveUndistributedEarningsAllocationRateOfOneClassOverOtherClass" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EarningsPerShareDilutedLineItems" xlink:to="ExcessiveUndistributedEarningsAllocationRateOfOneClassOverOtherClass" xlink:title="definition: EarningsPerShareDilutedLineItems to ExcessiveUndistributedEarningsAllocationRateOfOneClassOverOtherClass" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_EarningPerShareTwoClassMethodAbstract" xlink:label="EarningPerShareTwoClassMethodAbstract" xlink:title="EarningPerShareTwoClassMethodAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EarningsPerShareDilutedLineItems" xlink:to="EarningPerShareTwoClassMethodAbstract" xlink:title="definition: EarningsPerShareDilutedLineItems to EarningPerShareTwoClassMethodAbstract" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_NumeratorAbstract" xlink:label="NumeratorAbstract" xlink:title="NumeratorAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EarningsPerShareDilutedLineItems" xlink:to="NumeratorAbstract" xlink:title="definition: EarningsPerShareDilutedLineItems to NumeratorAbstract" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_UndistributedEarningsAllocationBasicAndDilutedAbstract" xlink:label="UndistributedEarningsAllocationBasicAndDilutedAbstract" xlink:title="UndistributedEarningsAllocationBasicAndDilutedAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EarningsPerShareDilutedLineItems" xlink:to="UndistributedEarningsAllocationBasicAndDilutedAbstract" xlink:title="definition: EarningsPerShareDilutedLineItems to UndistributedEarningsAllocationBasicAndDilutedAbstract" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_NetEarningsAllocationBasicAndDilutedAbstract" xlink:label="NetEarningsAllocationBasicAndDilutedAbstract" xlink:title="NetEarningsAllocationBasicAndDilutedAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EarningsPerShareDilutedLineItems" xlink:to="NetEarningsAllocationBasicAndDilutedAbstract" xlink:title="definition: EarningsPerShareDilutedLineItems to NetEarningsAllocationBasicAndDilutedAbstract" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_DenominatorAbstract" xlink:label="DenominatorAbstract" xlink:title="DenominatorAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EarningsPerShareDilutedLineItems" xlink:to="DenominatorAbstract" xlink:title="definition: EarningsPerShareDilutedLineItems to DenominatorAbstract" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:label="WeightedAverageNumberOfSharesOutstandingAbstract" xlink:title="WeightedAverageNumberOfSharesOutstandingAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EarningsPerShareDilutedLineItems" xlink:to="WeightedAverageNumberOfSharesOutstandingAbstract" xlink:title="definition: EarningsPerShareDilutedLineItems to WeightedAverageNumberOfSharesOutstandingAbstract" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EarningsPerShareBasicAndDilutedAbstract" xlink:label="EarningsPerShareBasicAndDilutedAbstract" xlink:title="EarningsPerShareBasicAndDilutedAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EarningsPerShareDilutedLineItems" xlink:to="EarningsPerShareBasicAndDilutedAbstract" xlink:title="definition: EarningsPerShareDilutedLineItems to EarningsPerShareBasicAndDilutedAbstract" order="9.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EarningsPerShareBasicAndDiluted" xlink:label="EarningsPerShareBasicAndDiluted" xlink:title="EarningsPerShareBasicAndDiluted" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EarningsPerShareDilutedLineItems" xlink:to="EarningsPerShareBasicAndDiluted" xlink:title="definition: EarningsPerShareDilutedLineItems to EarningsPerShareBasicAndDiluted" order="10.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:label="WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:title="WeightedAverageNumberOfShareOutstandingBasicAndDiluted" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EarningsPerShareDilutedLineItems" xlink:to="WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:title="definition: EarningsPerShareDilutedLineItems to WeightedAverageNumberOfShareOutstandingBasicAndDiluted" order="11.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="NetIncomeLoss" xlink:title="NetIncomeLoss" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EarningsPerShareDilutedLineItems" xlink:to="NetIncomeLoss" xlink:title="definition: EarningsPerShareDilutedLineItems to NetIncomeLoss" order="12.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_UndistributedEarningsDiluted" xlink:label="UndistributedEarningsDiluted" xlink:title="UndistributedEarningsDiluted" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EarningsPerShareDilutedLineItems" xlink:to="UndistributedEarningsDiluted" xlink:title="definition: EarningsPerShareDilutedLineItems to UndistributedEarningsDiluted" order="13.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_Dividends" xlink:label="Dividends" xlink:title="Dividends" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EarningsPerShareDilutedLineItems" xlink:to="Dividends" xlink:title="definition: EarningsPerShareDilutedLineItems to Dividends" order="14.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_UndistributedEarnings" xlink:label="UndistributedEarnings" xlink:title="UndistributedEarnings" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EarningsPerShareDilutedLineItems" xlink:to="UndistributedEarnings" xlink:title="definition: EarningsPerShareDilutedLineItems to UndistributedEarnings" order="15.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfEarningsPerShareDilutedByCommonClassTable" xlink:label="ScheduleOfEarningsPerShareDilutedByCommonClassTable" xlink:title="ScheduleOfEarningsPerShareDilutedByCommonClassTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="EarningsPerShareDilutedLineItems" xlink:to="ScheduleOfEarningsPerShareDilutedByCommonClassTable" xlink:title="definition: EarningsPerShareDilutedLineItems to ScheduleOfEarningsPerShareDilutedByCommonClassTable" order="16.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="StatementClassOfStockAxis" xlink:title="StatementClassOfStockAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfEarningsPerShareDilutedByCommonClassTable" xlink:to="StatementClassOfStockAxis" xlink:title="definition: ScheduleOfEarningsPerShareDilutedByCommonClassTable to StatementClassOfStockAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain_2" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain_2" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="CommonClassAMember" xlink:title="CommonClassAMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="CommonClassAMember" xlink:title="definition: ClassOfStockDomain to CommonClassAMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="CommonClassBMember" xlink:title="CommonClassBMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="CommonClassBMember" xlink:title="definition: ClassOfStockDomain to CommonClassBMember" order="2.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/AcquisitionsDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="BusinessAcquisitionLineItems" xlink:title="BusinessAcquisitionLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:title="PaymentsToAcquireBusinessesNetOfCashAcquired" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:title="definition: BusinessAcquisitionLineItems to PaymentsToAcquireBusinessesNetOfCashAcquired" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="BusinessCombinationAcquisitionRelatedCosts" xlink:title="BusinessCombinationAcquisitionRelatedCosts" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationAcquisitionRelatedCosts" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationAcquisitionRelatedCosts" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:label="EquityMethodInvestmentOwnershipPercentage" xlink:title="EquityMethodInvestmentOwnershipPercentage" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="EquityMethodInvestmentOwnershipPercentage" xlink:title="definition: BusinessAcquisitionLineItems to EquityMethodInvestmentOwnershipPercentage" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SalesRevenueGoodsNet" xlink:label="SalesRevenueGoodsNet" xlink:title="SalesRevenueGoodsNet" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="SalesRevenueGoodsNet" xlink:title="definition: BusinessAcquisitionLineItems to SalesRevenueGoodsNet" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="NetIncomeLoss" xlink:title="NetIncomeLoss" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="NetIncomeLoss" xlink:title="definition: BusinessAcquisitionLineItems to NetIncomeLoss" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_AcquisitionRelatedCostsExcludedFromProFormaNetEarnings" xlink:label="AcquisitionRelatedCostsExcludedFromProFormaNetEarnings" xlink:title="AcquisitionRelatedCostsExcludedFromProFormaNetEarnings" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="AcquisitionRelatedCostsExcludedFromProFormaNetEarnings" xlink:title="definition: BusinessAcquisitionLineItems to AcquisitionRelatedCostsExcludedFromProFormaNetEarnings" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_AcquisitionRelatedCostsIncurredButExcludedFromProFormaEarningsDuringPeriodAfterTax" xlink:label="AcquisitionRelatedCostsIncurredButExcludedFromProFormaEarningsDuringPeriodAfterTax" xlink:title="AcquisitionRelatedCostsIncurredButExcludedFromProFormaEarningsDuringPeriodAfterTax" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="AcquisitionRelatedCostsIncurredButExcludedFromProFormaEarningsDuringPeriodAfterTax" xlink:title="definition: BusinessAcquisitionLineItems to AcquisitionRelatedCostsIncurredButExcludedFromProFormaEarningsDuringPeriodAfterTax" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_NonrecurringExpenseRelatedToFairValueAdjustmentsExcludedFromProFormaNetEarnings" xlink:label="NonrecurringExpenseRelatedToFairValueAdjustmentsExcludedFromProFormaNetEarnings" xlink:title="NonrecurringExpenseRelatedToFairValueAdjustmentsExcludedFromProFormaNetEarnings" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="NonrecurringExpenseRelatedToFairValueAdjustmentsExcludedFromProFormaNetEarnings" xlink:title="definition: BusinessAcquisitionLineItems to NonrecurringExpenseRelatedToFairValueAdjustmentsExcludedFromProFormaNetEarnings" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_FairValueAdjustmentsExcludedFromProFormNetEarningsAfterTax" xlink:label="FairValueAdjustmentsExcludedFromProFormNetEarningsAfterTax" xlink:title="FairValueAdjustmentsExcludedFromProFormNetEarningsAfterTax" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="FairValueAdjustmentsExcludedFromProFormNetEarningsAfterTax" xlink:title="definition: BusinessAcquisitionLineItems to FairValueAdjustmentsExcludedFromProFormNetEarningsAfterTax" order="9.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterestAbstract" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterestAbstract" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterestAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterestAbstract" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterestAbstract" order="10.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionProFormaInformationAbstract" xlink:label="BusinessAcquisitionProFormaInformationAbstract" xlink:title="BusinessAcquisitionProFormaInformationAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessAcquisitionProFormaInformationAbstract" xlink:title="definition: BusinessAcquisitionLineItems to BusinessAcquisitionProFormaInformationAbstract" order="11.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionsProFormaRevenue" xlink:label="BusinessAcquisitionsProFormaRevenue" xlink:title="BusinessAcquisitionsProFormaRevenue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessAcquisitionsProFormaRevenue" xlink:title="definition: BusinessAcquisitionLineItems to BusinessAcquisitionsProFormaRevenue" order="12.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:label="BusinessAcquisitionsProFormaNetIncomeLoss" xlink:title="BusinessAcquisitionsProFormaNetIncomeLoss" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessAcquisitionsProFormaNetIncomeLoss" xlink:title="definition: BusinessAcquisitionLineItems to BusinessAcquisitionsProFormaNetIncomeLoss" order="13.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_BusinessAcquisitionProFormaEarningsPerShareBasicAndDiluted" xlink:label="BusinessAcquisitionProFormaEarningsPerShareBasicAndDiluted" xlink:title="BusinessAcquisitionProFormaEarningsPerShareBasicAndDiluted" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessAcquisitionProFormaEarningsPerShareBasicAndDiluted" xlink:title="definition: BusinessAcquisitionLineItems to BusinessAcquisitionProFormaEarningsPerShareBasicAndDiluted" order="14.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract" order="15.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract" order="16.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" order="17.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_Goodwill" xlink:label="Goodwill" xlink:title="Goodwill" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="Goodwill" xlink:title="definition: BusinessAcquisitionLineItems to Goodwill" order="18.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" order="19.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:label="BusinessCombinationConsiderationTransferredAbstract" xlink:title="BusinessCombinationConsiderationTransferredAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationConsiderationTransferredAbstract" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationConsiderationTransferredAbstract" order="20.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="PaymentsToAcquireBusinessesGross" xlink:title="PaymentsToAcquireBusinessesGross" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="PaymentsToAcquireBusinessesGross" xlink:title="definition: BusinessAcquisitionLineItems to PaymentsToAcquireBusinessesGross" order="21.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred" xlink:label="BusinessCombinationConsiderationTransferredLiabilitiesIncurred" xlink:title="BusinessCombinationConsiderationTransferredLiabilitiesIncurred" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationConsiderationTransferredLiabilitiesIncurred" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationConsiderationTransferredLiabilitiesIncurred" order="22.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="BusinessCombinationConsiderationTransferred1" xlink:title="BusinessCombinationConsiderationTransferred1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationConsiderationTransferred1" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationConsiderationTransferred1" order="23.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_BusinessCombinationContingentConsiderationAtFairValue" xlink:label="BusinessCombinationContingentConsiderationAtFairValue" xlink:title="BusinessCombinationContingentConsiderationAtFairValue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationContingentConsiderationAtFairValue" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationContingentConsiderationAtFairValue" order="24.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_BusinessCombinationCostOfAcquiredEntityPurchasePrice" xlink:label="BusinessCombinationCostOfAcquiredEntityPurchasePrice" xlink:title="BusinessCombinationCostOfAcquiredEntityPurchasePrice" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationCostOfAcquiredEntityPurchasePrice" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationCostOfAcquiredEntityPurchasePrice" order="25.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" order="26.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccruedExpenses" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccruedExpenses" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccruedExpenses" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccruedExpenses" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccruedExpenses" order="27.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentIncomeTaxesPayable" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentIncomeTaxesPayable" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentIncomeTaxesPayable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentIncomeTaxesPayable" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentIncomeTaxesPayable" order="28.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilitiesNoncurrent" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilitiesNoncurrent" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilitiesNoncurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilitiesNoncurrent" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilitiesNoncurrent" order="29.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt" order="30.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther" order="31.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" order="32.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" order="33.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" order="34.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" order="35.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" order="36.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" order="37.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" order="38.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" order="39.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets" order="40.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:title="definition: BusinessAcquisitionLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" order="41.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:title="ScheduleOfBusinessAcquisitionsByAcquisitionTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="BusinessAcquisitionLineItems" xlink:to="ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:title="definition: BusinessAcquisitionLineItems to ScheduleOfBusinessAcquisitionsByAcquisitionTable" order="42.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="BusinessAcquisitionAxis" xlink:title="BusinessAcquisitionAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="BusinessAcquisitionAxis" xlink:title="definition: ScheduleOfBusinessAcquisitionsByAcquisitionTable to BusinessAcquisitionAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="BusinessAcquisitionAcquireeDomain" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="BusinessAcquisitionAxis" xlink:to="BusinessAcquisitionAcquireeDomain" xlink:title="definition: BusinessAcquisitionAxis to BusinessAcquisitionAcquireeDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="BusinessAcquisitionAcquireeDomain_2" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="BusinessAcquisitionAxis" xlink:to="BusinessAcquisitionAcquireeDomain_2" xlink:title="definition: BusinessAcquisitionAxis to BusinessAcquisitionAcquireeDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_PowerSolutionsMember" xlink:label="PowerSolutionsMember" xlink:title="PowerSolutionsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="PowerSolutionsMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to PowerSolutionsMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_TrpMember" xlink:label="TrpMember" xlink:title="TrpMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="TrpMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to TrpMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_ArrayMember" xlink:label="ArrayMember" xlink:title="ArrayMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="ArrayMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to ArrayMember" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_AcquiredCompaniesMember" xlink:label="AcquiredCompaniesMember" xlink:title="AcquiredCompaniesMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="AcquiredCompaniesMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to AcquiredCompaniesMember" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementGeographicalAxis" xlink:label="StatementGeographicalAxis" xlink:title="StatementGeographicalAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="StatementGeographicalAxis" xlink:title="definition: ScheduleOfBusinessAcquisitionsByAcquisitionTable to StatementGeographicalAxis" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SegmentGeographicalDomain" xlink:label="SegmentGeographicalDomain" xlink:title="SegmentGeographicalDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementGeographicalAxis" xlink:to="SegmentGeographicalDomain" xlink:title="definition: StatementGeographicalAxis to SegmentGeographicalDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SegmentGeographicalDomain" xlink:label="SegmentGeographicalDomain_2" xlink:title="SegmentGeographicalDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="StatementGeographicalAxis" xlink:to="SegmentGeographicalDomain_2" xlink:title="definition: StatementGeographicalAxis to SegmentGeographicalDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NorthAmericaMember" xlink:label="NorthAmericaMember" xlink:title="NorthAmericaMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SegmentGeographicalDomain" xlink:to="NorthAmericaMember" xlink:title="definition: SegmentGeographicalDomain to NorthAmericaMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EuropeMember" xlink:label="EuropeMember" xlink:title="EuropeMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SegmentGeographicalDomain" xlink:to="EuropeMember" xlink:title="definition: SegmentGeographicalDomain to EuropeMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="StatementClassOfStockAxis" xlink:title="StatementClassOfStockAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="StatementClassOfStockAxis" xlink:title="definition: ScheduleOfBusinessAcquisitionsByAcquisitionTable to StatementClassOfStockAxis" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain_2" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain_2" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="CommonClassAMember" xlink:title="CommonClassAMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="CommonClassAMember" xlink:title="definition: ClassOfStockDomain to CommonClassAMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="CommonClassBMember" xlink:title="CommonClassBMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="CommonClassBMember" xlink:title="definition: ClassOfStockDomain to CommonClassBMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="StatementScenarioAxis" xlink:title="StatementScenarioAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="StatementScenarioAxis" xlink:title="definition: ScheduleOfBusinessAcquisitionsByAcquisitionTable to StatementScenarioAxis" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="ScenarioUnspecifiedDomain" xlink:title="ScenarioUnspecifiedDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementScenarioAxis" xlink:to="ScenarioUnspecifiedDomain" xlink:title="definition: StatementScenarioAxis to ScenarioUnspecifiedDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="ScenarioUnspecifiedDomain_2" xlink:title="ScenarioUnspecifiedDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="StatementScenarioAxis" xlink:to="ScenarioUnspecifiedDomain_2" xlink:title="definition: StatementScenarioAxis to ScenarioUnspecifiedDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScenarioPreviouslyReportedMember" xlink:label="ScenarioPreviouslyReportedMember" xlink:title="ScenarioPreviouslyReportedMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ScenarioUnspecifiedDomain" xlink:to="ScenarioPreviouslyReportedMember" xlink:title="definition: ScenarioUnspecifiedDomain to ScenarioPreviouslyReportedMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScenarioAdjustmentMember" xlink:label="ScenarioAdjustmentMember" xlink:title="ScenarioAdjustmentMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ScenarioUnspecifiedDomain" xlink:to="ScenarioAdjustmentMember" xlink:title="definition: ScenarioUnspecifiedDomain to ScenarioAdjustmentMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScenarioActualMember" xlink:label="ScenarioActualMember" xlink:title="ScenarioActualMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ScenarioUnspecifiedDomain" xlink:to="ScenarioActualMember" xlink:title="definition: ScenarioUnspecifiedDomain to ScenarioActualMember" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:title="FiniteLivedIntangibleAssetsByMajorClassAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:title="definition: ScheduleOfBusinessAcquisitionsByAcquisitionTable to FiniteLivedIntangibleAssetsByMajorClassAxis" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:title="FiniteLivedIntangibleAssetsMajorClassNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:title="definition: FiniteLivedIntangibleAssetsByMajorClassAxis to FiniteLivedIntangibleAssetsMajorClassNameDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="FiniteLivedIntangibleAssetsMajorClassNameDomain_2" xlink:title="FiniteLivedIntangibleAssetsMajorClassNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="FiniteLivedIntangibleAssetsMajorClassNameDomain_2" xlink:title="definition: FiniteLivedIntangibleAssetsByMajorClassAxis to FiniteLivedIntangibleAssetsMajorClassNameDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_TrademarksMember" xlink:label="TrademarksMember" xlink:title="TrademarksMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="TrademarksMember" xlink:title="definition: FiniteLivedIntangibleAssetsMajorClassNameDomain to TrademarksMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_UnpatentedTechnologyMember" xlink:label="UnpatentedTechnologyMember" xlink:title="UnpatentedTechnologyMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="UnpatentedTechnologyMember" xlink:title="definition: FiniteLivedIntangibleAssetsMajorClassNameDomain to UnpatentedTechnologyMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="CustomerRelationshipsMember" xlink:title="CustomerRelationshipsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="CustomerRelationshipsMember" xlink:title="definition: FiniteLivedIntangibleAssetsMajorClassNameDomain to CustomerRelationshipsMember" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NoncompeteAgreementsMember" xlink:label="NoncompeteAgreementsMember" xlink:title="NoncompeteAgreementsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="NoncompeteAgreementsMember" xlink:title="definition: FiniteLivedIntangibleAssetsMajorClassNameDomain to NoncompeteAgreementsMember" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeAxis" xlink:label="RangeAxis" xlink:title="RangeAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="RangeAxis" xlink:title="definition: ScheduleOfBusinessAcquisitionsByAcquisitionTable to RangeAxis" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeMember" xlink:label="RangeMember" xlink:title="RangeMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="RangeAxis" xlink:to="RangeMember" xlink:title="definition: RangeAxis to RangeMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeMember" xlink:label="RangeMember_2" xlink:title="RangeMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="RangeAxis" xlink:to="RangeMember_2" xlink:title="definition: RangeAxis to RangeMember_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MaximumMember" xlink:label="MaximumMember" xlink:title="MaximumMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RangeMember" xlink:to="MaximumMember" xlink:title="definition: RangeMember to MaximumMember" order="1.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/FairValueMeasurementsDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:title="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:label="OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:title="OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AvailableForSaleSecurities" xlink:label="AvailableForSaleSecurities" xlink:title="AvailableForSaleSecurities" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="AvailableForSaleSecurities" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to AvailableForSaleSecurities" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" xlink:label="AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" xlink:title="AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AssetsFairValueDisclosureAbstract" xlink:label="AssetsFairValueDisclosureAbstract" xlink:title="AssetsFairValueDisclosureAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="AssetsFairValueDisclosureAbstract" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to AssetsFairValueDisclosureAbstract" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebtFairValue" xlink:label="LongTermDebtFairValue" xlink:title="LongTermDebtFairValue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="LongTermDebtFairValue" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to LongTermDebtFairValue" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebt" xlink:label="LongTermDebt" xlink:title="LongTermDebt" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="LongTermDebt" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to LongTermDebt" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_InvestmentsHeldInRabbiTrustFairValueDisclosure" xlink:label="InvestmentsHeldInRabbiTrustFairValueDisclosure" xlink:title="InvestmentsHeldInRabbiTrustFairValueDisclosure" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="InvestmentsHeldInRabbiTrustFairValueDisclosure" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to InvestmentsHeldInRabbiTrustFairValueDisclosure" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_MarketableSecuritiesFairValueDisclosure" xlink:label="MarketableSecuritiesFairValueDisclosure" xlink:title="MarketableSecuritiesFairValueDisclosure" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="MarketableSecuritiesFairValueDisclosure" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to MarketableSecuritiesFairValueDisclosure" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="AssetsFairValueDisclosure" xlink:title="AssetsFairValueDisclosure" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="AssetsFairValueDisclosure" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to AssetsFairValueDisclosure" order="9.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:title="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" order="10.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="FairValueByMeasurementFrequencyAxis" xlink:title="FairValueByMeasurementFrequencyAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="FairValueByMeasurementFrequencyAxis" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable to FairValueByMeasurementFrequencyAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="FairValueMeasurementFrequencyDomain" xlink:title="FairValueMeasurementFrequencyDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="FairValueByMeasurementFrequencyAxis" xlink:to="FairValueMeasurementFrequencyDomain" xlink:title="definition: FairValueByMeasurementFrequencyAxis to FairValueMeasurementFrequencyDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="FairValueMeasurementFrequencyDomain_2" xlink:title="FairValueMeasurementFrequencyDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="FairValueByMeasurementFrequencyAxis" xlink:to="FairValueMeasurementFrequencyDomain_2" xlink:title="definition: FairValueByMeasurementFrequencyAxis to FairValueMeasurementFrequencyDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="FairValueMeasurementsRecurringMember" xlink:title="FairValueMeasurementsRecurringMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueMeasurementFrequencyDomain" xlink:to="FairValueMeasurementsRecurringMember" xlink:title="definition: FairValueMeasurementFrequencyDomain to FairValueMeasurementsRecurringMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="FairValueByFairValueHierarchyLevelAxis" xlink:title="FairValueByFairValueHierarchyLevelAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="FairValueByFairValueHierarchyLevelAxis" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable to FairValueByFairValueHierarchyLevelAxis" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="FairValueMeasurementsFairValueHierarchyDomain" xlink:title="FairValueMeasurementsFairValueHierarchyDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="FairValueByFairValueHierarchyLevelAxis" xlink:to="FairValueMeasurementsFairValueHierarchyDomain" xlink:title="definition: FairValueByFairValueHierarchyLevelAxis to FairValueMeasurementsFairValueHierarchyDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="FairValueMeasurementsFairValueHierarchyDomain_2" xlink:title="FairValueMeasurementsFairValueHierarchyDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="FairValueByFairValueHierarchyLevelAxis" xlink:to="FairValueMeasurementsFairValueHierarchyDomain_2" xlink:title="definition: FairValueByFairValueHierarchyLevelAxis to FairValueMeasurementsFairValueHierarchyDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="FairValueInputsLevel1Member" xlink:title="FairValueInputsLevel1Member" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueMeasurementsFairValueHierarchyDomain" xlink:to="FairValueInputsLevel1Member" xlink:title="definition: FairValueMeasurementsFairValueHierarchyDomain to FairValueInputsLevel1Member" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="FairValueInputsLevel2Member" xlink:title="FairValueInputsLevel2Member" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueMeasurementsFairValueHierarchyDomain" xlink:to="FairValueInputsLevel2Member" xlink:title="definition: FairValueMeasurementsFairValueHierarchyDomain to FairValueInputsLevel2Member" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="FairValueInputsLevel3Member" xlink:title="FairValueInputsLevel3Member" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueMeasurementsFairValueHierarchyDomain" xlink:to="FairValueInputsLevel3Member" xlink:title="definition: FairValueMeasurementsFairValueHierarchyDomain to FairValueInputsLevel3Member" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="AwardTypeAxis" xlink:title="AwardTypeAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="AwardTypeAxis" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable to AwardTypeAxis" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="AwardTypeAxis" xlink:to="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="definition: AwardTypeAxis to ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_2" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="AwardTypeAxis" xlink:to="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_2" xlink:title="definition: AwardTypeAxis to ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockCompensationPlanMember" xlink:label="StockCompensationPlanMember" xlink:title="StockCompensationPlanMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="StockCompensationPlanMember" xlink:title="definition: ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain to StockCompensationPlanMember" order="1.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/InventoriesDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InventoryLineItems" xlink:label="InventoryLineItems" xlink:title="InventoryLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="InventoryLineItems" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:title="definition: InventoryLineItems to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InventoryCurrentTable" xlink:label="InventoryCurrentTable" xlink:title="InventoryCurrentTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="InventoryLineItems" xlink:to="InventoryCurrentTable" xlink:title="definition: InventoryLineItems to InventoryCurrentTable" order="2.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="BusinessAcquisitionAxis" xlink:title="BusinessAcquisitionAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="InventoryCurrentTable" xlink:to="BusinessAcquisitionAxis" xlink:title="definition: InventoryCurrentTable to BusinessAcquisitionAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="BusinessAcquisitionAcquireeDomain" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="BusinessAcquisitionAxis" xlink:to="BusinessAcquisitionAcquireeDomain" xlink:title="definition: BusinessAcquisitionAxis to BusinessAcquisitionAcquireeDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="BusinessAcquisitionAcquireeDomain_2" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="BusinessAcquisitionAxis" xlink:to="BusinessAcquisitionAcquireeDomain_2" xlink:title="definition: BusinessAcquisitionAxis to BusinessAcquisitionAcquireeDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_PowerSolutionsMember" xlink:label="PowerSolutionsMember" xlink:title="PowerSolutionsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="PowerSolutionsMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to PowerSolutionsMember" order="1.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/PropertyPlantAndEquipmentDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="PropertyPlantAndEquipmentLineItems" xlink:title="PropertyPlantAndEquipmentLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNetAbstract" xlink:label="PropertyPlantAndEquipmentNetAbstract" xlink:title="PropertyPlantAndEquipmentNetAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentLineItems" xlink:to="PropertyPlantAndEquipmentNetAbstract" xlink:title="definition: PropertyPlantAndEquipmentLineItems to PropertyPlantAndEquipmentNetAbstract" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="PropertyPlantAndEquipmentGross" xlink:title="PropertyPlantAndEquipmentGross" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentLineItems" xlink:to="PropertyPlantAndEquipmentGross" xlink:title="definition: PropertyPlantAndEquipmentLineItems to PropertyPlantAndEquipmentGross" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:title="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentLineItems" xlink:to="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:title="definition: PropertyPlantAndEquipmentLineItems to AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="PropertyPlantAndEquipmentNet" xlink:title="PropertyPlantAndEquipmentNet" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentLineItems" xlink:to="PropertyPlantAndEquipmentNet" xlink:title="definition: PropertyPlantAndEquipmentLineItems to PropertyPlantAndEquipmentNet" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="ScheduleOfPropertyPlantAndEquipmentTable" xlink:title="ScheduleOfPropertyPlantAndEquipmentTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="PropertyPlantAndEquipmentLineItems" xlink:to="ScheduleOfPropertyPlantAndEquipmentTable" xlink:title="definition: PropertyPlantAndEquipmentLineItems to ScheduleOfPropertyPlantAndEquipmentTable" order="5.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="PropertyPlantAndEquipmentByTypeAxis" xlink:title="PropertyPlantAndEquipmentByTypeAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="PropertyPlantAndEquipmentByTypeAxis" xlink:title="definition: ScheduleOfPropertyPlantAndEquipmentTable to PropertyPlantAndEquipmentByTypeAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="PropertyPlantAndEquipmentTypeDomain" xlink:title="PropertyPlantAndEquipmentTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="PropertyPlantAndEquipmentByTypeAxis" xlink:to="PropertyPlantAndEquipmentTypeDomain" xlink:title="definition: PropertyPlantAndEquipmentByTypeAxis to PropertyPlantAndEquipmentTypeDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="PropertyPlantAndEquipmentTypeDomain_2" xlink:title="PropertyPlantAndEquipmentTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="PropertyPlantAndEquipmentByTypeAxis" xlink:to="PropertyPlantAndEquipmentTypeDomain_2" xlink:title="definition: PropertyPlantAndEquipmentByTypeAxis to PropertyPlantAndEquipmentTypeDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LandMember" xlink:label="LandMember" xlink:title="LandMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentTypeDomain" xlink:to="LandMember" xlink:title="definition: PropertyPlantAndEquipmentTypeDomain to LandMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BuildingAndBuildingImprovementsMember" xlink:label="BuildingAndBuildingImprovementsMember" xlink:title="BuildingAndBuildingImprovementsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentTypeDomain" xlink:to="BuildingAndBuildingImprovementsMember" xlink:title="definition: PropertyPlantAndEquipmentTypeDomain to BuildingAndBuildingImprovementsMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MachineryAndEquipmentMember" xlink:label="MachineryAndEquipmentMember" xlink:title="MachineryAndEquipmentMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentTypeDomain" xlink:to="MachineryAndEquipmentMember" xlink:title="definition: PropertyPlantAndEquipmentTypeDomain to MachineryAndEquipmentMember" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AssetUnderConstructionMember" xlink:label="AssetUnderConstructionMember" xlink:title="AssetUnderConstructionMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentTypeDomain" xlink:to="AssetUnderConstructionMember" xlink:title="definition: PropertyPlantAndEquipmentTypeDomain to AssetUnderConstructionMember" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="BusinessAcquisitionAxis" xlink:title="BusinessAcquisitionAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="BusinessAcquisitionAxis" xlink:title="definition: ScheduleOfPropertyPlantAndEquipmentTable to BusinessAcquisitionAxis" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="BusinessAcquisitionAcquireeDomain" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="BusinessAcquisitionAxis" xlink:to="BusinessAcquisitionAcquireeDomain" xlink:title="definition: BusinessAcquisitionAxis to BusinessAcquisitionAcquireeDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="BusinessAcquisitionAcquireeDomain_2" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="BusinessAcquisitionAxis" xlink:to="BusinessAcquisitionAcquireeDomain_2" xlink:title="definition: BusinessAcquisitionAxis to BusinessAcquisitionAcquireeDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_PowerSolutionsMember" xlink:label="PowerSolutionsMember" xlink:title="PowerSolutionsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="PowerSolutionsMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to PowerSolutionsMember" order="1.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/BusinessSegmentInformationDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="SegmentReportingInformationLineItems" xlink:title="SegmentReportingInformationLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract" xlink:label="ReconciliationFromSegmentTotalsToConsolidatedAbstract" xlink:title="ReconciliationFromSegmentTotalsToConsolidatedAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SegmentReportingInformationLineItems" xlink:to="ReconciliationFromSegmentTotalsToConsolidatedAbstract" xlink:title="definition: SegmentReportingInformationLineItems to ReconciliationFromSegmentTotalsToConsolidatedAbstract" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_TotalSegmentSalesAbstract" xlink:label="TotalSegmentSalesAbstract" xlink:title="TotalSegmentSalesAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SegmentReportingInformationLineItems" xlink:to="TotalSegmentSalesAbstract" xlink:title="definition: SegmentReportingInformationLineItems to TotalSegmentSalesAbstract" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedAbstract" xlink:label="ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedAbstract" xlink:title="ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SegmentReportingInformationLineItems" xlink:to="ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedAbstract" xlink:title="definition: SegmentReportingInformationLineItems to ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedAbstract" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="AssetsAbstract" xlink:title="AssetsAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SegmentReportingInformationLineItems" xlink:to="AssetsAbstract" xlink:title="definition: SegmentReportingInformationLineItems to AssetsAbstract" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_AssetsNetExcludingGoodwill" xlink:label="AssetsNetExcludingGoodwill" xlink:title="AssetsNetExcludingGoodwill" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SegmentReportingInformationLineItems" xlink:to="AssetsNetExcludingGoodwill" xlink:title="definition: SegmentReportingInformationLineItems to AssetsNetExcludingGoodwill" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GoodwillNotAllocatedAmount" xlink:label="GoodwillNotAllocatedAmount" xlink:title="GoodwillNotAllocatedAmount" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SegmentReportingInformationLineItems" xlink:to="GoodwillNotAllocatedAmount" xlink:title="definition: SegmentReportingInformationLineItems to GoodwillNotAllocatedAmount" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_Assets" xlink:label="Assets" xlink:title="Assets" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SegmentReportingInformationLineItems" xlink:to="Assets" xlink:title="definition: SegmentReportingInformationLineItems to Assets" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="OperatingIncomeLoss" xlink:title="OperatingIncomeLoss" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SegmentReportingInformationLineItems" xlink:to="OperatingIncomeLoss" xlink:title="definition: SegmentReportingInformationLineItems to OperatingIncomeLoss" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SalesRevenueGoodsNet" xlink:label="SalesRevenueGoodsNet" xlink:title="SalesRevenueGoodsNet" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SegmentReportingInformationLineItems" xlink:to="SalesRevenueGoodsNet" xlink:title="definition: SegmentReportingInformationLineItems to SalesRevenueGoodsNet" order="9.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="ScheduleOfSegmentReportingInformationBySegmentTable" xlink:title="ScheduleOfSegmentReportingInformationBySegmentTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="SegmentReportingInformationLineItems" xlink:to="ScheduleOfSegmentReportingInformationBySegmentTable" xlink:title="definition: SegmentReportingInformationLineItems to ScheduleOfSegmentReportingInformationBySegmentTable" order="10.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementGeographicalAxis" xlink:label="StatementGeographicalAxis" xlink:title="StatementGeographicalAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="StatementGeographicalAxis" xlink:title="definition: ScheduleOfSegmentReportingInformationBySegmentTable to StatementGeographicalAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SegmentGeographicalDomain" xlink:label="SegmentGeographicalDomain" xlink:title="SegmentGeographicalDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementGeographicalAxis" xlink:to="SegmentGeographicalDomain" xlink:title="definition: StatementGeographicalAxis to SegmentGeographicalDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SegmentGeographicalDomain" xlink:label="SegmentGeographicalDomain_2" xlink:title="SegmentGeographicalDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="StatementGeographicalAxis" xlink:to="SegmentGeographicalDomain_2" xlink:title="definition: StatementGeographicalAxis to SegmentGeographicalDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NorthAmericaMember" xlink:label="NorthAmericaMember" xlink:title="NorthAmericaMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SegmentGeographicalDomain" xlink:to="NorthAmericaMember" xlink:title="definition: SegmentGeographicalDomain to NorthAmericaMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AsiaMember" xlink:label="AsiaMember" xlink:title="AsiaMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SegmentGeographicalDomain" xlink:to="AsiaMember" xlink:title="definition: SegmentGeographicalDomain to AsiaMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EuropeMember" xlink:label="EuropeMember" xlink:title="EuropeMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SegmentGeographicalDomain" xlink:to="EuropeMember" xlink:title="definition: SegmentGeographicalDomain to EuropeMember" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IntersegmentEliminationMember" xlink:label="IntersegmentEliminationMember" xlink:title="IntersegmentEliminationMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SegmentGeographicalDomain" xlink:to="IntersegmentEliminationMember" xlink:title="definition: SegmentGeographicalDomain to IntersegmentEliminationMember" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConsolidationItemsAxis" xlink:label="ConsolidationItemsAxis" xlink:title="ConsolidationItemsAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="ConsolidationItemsAxis" xlink:title="definition: ScheduleOfSegmentReportingInformationBySegmentTable to ConsolidationItemsAxis" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConsolidationItemsDomain" xlink:label="ConsolidationItemsDomain" xlink:title="ConsolidationItemsDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="ConsolidationItemsAxis" xlink:to="ConsolidationItemsDomain" xlink:title="definition: ConsolidationItemsAxis to ConsolidationItemsDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConsolidationItemsDomain" xlink:label="ConsolidationItemsDomain_2" xlink:title="ConsolidationItemsDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="ConsolidationItemsAxis" xlink:to="ConsolidationItemsDomain_2" xlink:title="definition: ConsolidationItemsAxis to ConsolidationItemsDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ReportableGeographicalComponentsMember" xlink:label="ReportableGeographicalComponentsMember" xlink:title="ReportableGeographicalComponentsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ConsolidationItemsDomain" xlink:to="ReportableGeographicalComponentsMember" xlink:title="definition: ConsolidationItemsDomain to ReportableGeographicalComponentsMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="BusinessAcquisitionAxis" xlink:title="BusinessAcquisitionAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="BusinessAcquisitionAxis" xlink:title="definition: ScheduleOfSegmentReportingInformationBySegmentTable to BusinessAcquisitionAxis" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="BusinessAcquisitionAcquireeDomain" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="BusinessAcquisitionAxis" xlink:to="BusinessAcquisitionAcquireeDomain" xlink:title="definition: BusinessAcquisitionAxis to BusinessAcquisitionAcquireeDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="BusinessAcquisitionAcquireeDomain_2" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="BusinessAcquisitionAxis" xlink:to="BusinessAcquisitionAcquireeDomain_2" xlink:title="definition: BusinessAcquisitionAxis to BusinessAcquisitionAcquireeDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_ArrayMember" xlink:label="ArrayMember" xlink:title="ArrayMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="ArrayMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to ArrayMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_TrpMember" xlink:label="TrpMember" xlink:title="TrpMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="TrpMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to TrpMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_PowerSolutionsMember" xlink:label="PowerSolutionsMember" xlink:title="PowerSolutionsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="PowerSolutionsMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to PowerSolutionsMember" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_AcquiredCompaniesMember" xlink:label="AcquiredCompaniesMember" xlink:title="AcquiredCompaniesMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="AcquiredCompaniesMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to AcquiredCompaniesMember" order="4.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/IncomeTaxesDetails">
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_IncomeTaxesLineItems" xlink:label="IncomeTaxesLineItems" xlink:title="IncomeTaxesLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:label="UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:title="UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncomeTaxesLineItems" xlink:to="UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:title="definition: IncomeTaxesLineItems to UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilityForUncertainTaxPositionsCurrent" xlink:label="LiabilityForUncertainTaxPositionsCurrent" xlink:title="LiabilityForUncertainTaxPositionsCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncomeTaxesLineItems" xlink:to="LiabilityForUncertainTaxPositionsCurrent" xlink:title="definition: IncomeTaxesLineItems to LiabilityForUncertainTaxPositionsCurrent" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_LiabilityForUncertainTaxPositionsIncludedInLiabilityForUncertainTaxPositions" xlink:label="LiabilityForUncertainTaxPositionsIncludedInLiabilityForUncertainTaxPositions" xlink:title="LiabilityForUncertainTaxPositionsIncludedInLiabilityForUncertainTaxPositions" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncomeTaxesLineItems" xlink:to="LiabilityForUncertainTaxPositionsIncludedInLiabilityForUncertainTaxPositions" xlink:title="definition: IncomeTaxesLineItems to LiabilityForUncertainTaxPositionsIncludedInLiabilityForUncertainTaxPositions" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_PriorYearLiabilityUncertainTaxPositionsYear1" xlink:label="PriorYearLiabilityUncertainTaxPositionsYear1" xlink:title="PriorYearLiabilityUncertainTaxPositionsYear1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncomeTaxesLineItems" xlink:to="PriorYearLiabilityUncertainTaxPositionsYear1" xlink:title="definition: IncomeTaxesLineItems to PriorYearLiabilityUncertainTaxPositionsYear1" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" xlink:label="UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" xlink:title="UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncomeTaxesLineItems" xlink:to="UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" xlink:title="definition: IncomeTaxesLineItems to UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DeferredTaxLiabilities" xlink:label="DeferredTaxLiabilities" xlink:title="DeferredTaxLiabilities" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncomeTaxesLineItems" xlink:to="DeferredTaxLiabilities" xlink:title="definition: IncomeTaxesLineItems to DeferredTaxLiabilities" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_BusinessAcquisitionPurchasePriceAllocationDeferredTaxLiabilitiesCurrentAndNonCurrent" xlink:label="BusinessAcquisitionPurchasePriceAllocationDeferredTaxLiabilitiesCurrentAndNonCurrent" xlink:title="BusinessAcquisitionPurchasePriceAllocationDeferredTaxLiabilitiesCurrentAndNonCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncomeTaxesLineItems" xlink:to="BusinessAcquisitionPurchasePriceAllocationDeferredTaxLiabilitiesCurrentAndNonCurrent" xlink:title="definition: IncomeTaxesLineItems to BusinessAcquisitionPurchasePriceAllocationDeferredTaxLiabilitiesCurrentAndNonCurrent" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DeferredTaxAssetsNet" xlink:label="DeferredTaxAssetsNet" xlink:title="DeferredTaxAssetsNet" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncomeTaxesLineItems" xlink:to="DeferredTaxAssetsNet" xlink:title="definition: IncomeTaxesLineItems to DeferredTaxAssetsNet" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_ExpectedIncreaseInIncomeTaxBenefit" xlink:label="ExpectedIncreaseInIncomeTaxBenefit" xlink:title="ExpectedIncreaseInIncomeTaxBenefit" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncomeTaxesLineItems" xlink:to="ExpectedIncreaseInIncomeTaxBenefit" xlink:title="definition: IncomeTaxesLineItems to ExpectedIncreaseInIncomeTaxBenefit" order="9.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_IncreaseInIncomeTaxBenefit" xlink:label="IncreaseInIncomeTaxBenefit" xlink:title="IncreaseInIncomeTaxBenefit" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncomeTaxesLineItems" xlink:to="IncreaseInIncomeTaxBenefit" xlink:title="definition: IncomeTaxesLineItems to IncreaseInIncomeTaxBenefit" order="10.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_IncomeTaxesTable" xlink:label="IncomeTaxesTable" xlink:title="IncomeTaxesTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="IncomeTaxesLineItems" xlink:to="IncomeTaxesTable" xlink:title="definition: IncomeTaxesLineItems to IncomeTaxesTable" order="11.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis" xlink:label="IncomeTaxAuthorityAxis" xlink:title="IncomeTaxAuthorityAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="IncomeTaxesTable" xlink:to="IncomeTaxAuthorityAxis" xlink:title="definition: IncomeTaxesTable to IncomeTaxAuthorityAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="IncomeTaxAuthorityDomain" xlink:title="IncomeTaxAuthorityDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="IncomeTaxAuthorityAxis" xlink:to="IncomeTaxAuthorityDomain" xlink:title="definition: IncomeTaxAuthorityAxis to IncomeTaxAuthorityDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="IncomeTaxAuthorityDomain_2" xlink:title="IncomeTaxAuthorityDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="IncomeTaxAuthorityAxis" xlink:to="IncomeTaxAuthorityDomain_2" xlink:title="definition: IncomeTaxAuthorityAxis to IncomeTaxAuthorityDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DomesticCountryMember" xlink:label="DomesticCountryMember" xlink:title="DomesticCountryMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncomeTaxAuthorityDomain" xlink:to="DomesticCountryMember" xlink:title="definition: IncomeTaxAuthorityDomain to DomesticCountryMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StateAndLocalJurisdictionMember" xlink:label="StateAndLocalJurisdictionMember" xlink:title="StateAndLocalJurisdictionMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncomeTaxAuthorityDomain" xlink:to="StateAndLocalJurisdictionMember" xlink:title="definition: IncomeTaxAuthorityDomain to StateAndLocalJurisdictionMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ForeignCountryMember" xlink:label="ForeignCountryMember" xlink:title="ForeignCountryMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncomeTaxAuthorityDomain" xlink:to="ForeignCountryMember" xlink:title="definition: IncomeTaxAuthorityDomain to ForeignCountryMember" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementGeographicalAxis" xlink:label="StatementGeographicalAxis" xlink:title="StatementGeographicalAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="IncomeTaxesTable" xlink:to="StatementGeographicalAxis" xlink:title="definition: IncomeTaxesTable to StatementGeographicalAxis" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SegmentGeographicalDomain" xlink:label="SegmentGeographicalDomain" xlink:title="SegmentGeographicalDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementGeographicalAxis" xlink:to="SegmentGeographicalDomain" xlink:title="definition: StatementGeographicalAxis to SegmentGeographicalDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SegmentGeographicalDomain" xlink:label="SegmentGeographicalDomain_2" xlink:title="SegmentGeographicalDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="StatementGeographicalAxis" xlink:to="SegmentGeographicalDomain_2" xlink:title="definition: StatementGeographicalAxis to SegmentGeographicalDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AsiaMember" xlink:label="AsiaMember" xlink:title="AsiaMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SegmentGeographicalDomain" xlink:to="AsiaMember" xlink:title="definition: SegmentGeographicalDomain to AsiaMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EuropeMember" xlink:label="EuropeMember" xlink:title="EuropeMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SegmentGeographicalDomain" xlink:to="EuropeMember" xlink:title="definition: SegmentGeographicalDomain to EuropeMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="BusinessAcquisitionAxis" xlink:title="BusinessAcquisitionAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="IncomeTaxesTable" xlink:to="BusinessAcquisitionAxis" xlink:title="definition: IncomeTaxesTable to BusinessAcquisitionAxis" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="BusinessAcquisitionAcquireeDomain" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="BusinessAcquisitionAxis" xlink:to="BusinessAcquisitionAcquireeDomain" xlink:title="definition: BusinessAcquisitionAxis to BusinessAcquisitionAcquireeDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="BusinessAcquisitionAcquireeDomain_2" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="BusinessAcquisitionAxis" xlink:to="BusinessAcquisitionAcquireeDomain_2" xlink:title="definition: BusinessAcquisitionAxis to BusinessAcquisitionAcquireeDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_TrpMember" xlink:label="TrpMember" xlink:title="TrpMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="TrpMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to TrpMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_PowerSolutionsMember" xlink:label="PowerSolutionsMember" xlink:title="PowerSolutionsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="PowerSolutionsMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to PowerSolutionsMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_ArrayMember" xlink:label="ArrayMember" xlink:title="ArrayMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="ArrayMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to ArrayMember" order="3.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/AccruedExpensesDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="BusinessAcquisitionLineItems" xlink:title="BusinessAcquisitionLineItems" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_StandardWarrantyPeriodOfProduct" xlink:label="StandardWarrantyPeriodOfProduct" xlink:title="StandardWarrantyPeriodOfProduct" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="StandardWarrantyPeriodOfProduct" xlink:title="definition: BusinessAcquisitionLineItems to StandardWarrantyPeriodOfProduct" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MovementInStandardProductWarrantyAccrualRollForward" xlink:label="MovementInStandardProductWarrantyAccrualRollForward" xlink:title="MovementInStandardProductWarrantyAccrualRollForward" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="MovementInStandardProductWarrantyAccrualRollForward" xlink:title="definition: BusinessAcquisitionLineItems to MovementInStandardProductWarrantyAccrualRollForward" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StandardProductWarrantyAccrual" xlink:label="StandardProductWarrantyAccrual" xlink:title="StandardProductWarrantyAccrual" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="StandardProductWarrantyAccrual" xlink:title="definition: BusinessAcquisitionLineItems to StandardProductWarrantyAccrual" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_StandardProductWarrantyAccrualChargesAndCostsAccrued" xlink:label="StandardProductWarrantyAccrualChargesAndCostsAccrued" xlink:title="StandardProductWarrantyAccrualChargesAndCostsAccrued" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="StandardProductWarrantyAccrualChargesAndCostsAccrued" xlink:title="definition: BusinessAcquisitionLineItems to StandardProductWarrantyAccrualChargesAndCostsAccrued" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_StandardProductWarrantyAccrualAdjustmentsRelatedToPreExistingWarrantiesIncludingChangesInEstimates" xlink:label="StandardProductWarrantyAccrualAdjustmentsRelatedToPreExistingWarrantiesIncludingChangesInEstimates" xlink:title="StandardProductWarrantyAccrualAdjustmentsRelatedToPreExistingWarrantiesIncludingChangesInEstimates" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="StandardProductWarrantyAccrualAdjustmentsRelatedToPreExistingWarrantiesIncludingChangesInEstimates" xlink:title="definition: BusinessAcquisitionLineItems to StandardProductWarrantyAccrualAdjustmentsRelatedToPreExistingWarrantiesIncludingChangesInEstimates" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StandardProductWarrantyAccrualPayments" xlink:label="StandardProductWarrantyAccrualPayments" xlink:title="StandardProductWarrantyAccrualPayments" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="StandardProductWarrantyAccrualPayments" xlink:title="definition: BusinessAcquisitionLineItems to StandardProductWarrantyAccrualPayments" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StandardProductWarrantyAccrualCurrencyTranslationIncreaseDecrease" xlink:label="StandardProductWarrantyAccrualCurrencyTranslationIncreaseDecrease" xlink:title="StandardProductWarrantyAccrualCurrencyTranslationIncreaseDecrease" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionLineItems" xlink:to="StandardProductWarrantyAccrualCurrencyTranslationIncreaseDecrease" xlink:title="definition: BusinessAcquisitionLineItems to StandardProductWarrantyAccrualCurrencyTranslationIncreaseDecrease" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:title="ScheduleOfBusinessAcquisitionsByAcquisitionTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="BusinessAcquisitionLineItems" xlink:to="ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:title="definition: BusinessAcquisitionLineItems to ScheduleOfBusinessAcquisitionsByAcquisitionTable" order="8.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="BusinessAcquisitionAxis" xlink:title="BusinessAcquisitionAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="BusinessAcquisitionAxis" xlink:title="definition: ScheduleOfBusinessAcquisitionsByAcquisitionTable to BusinessAcquisitionAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="BusinessAcquisitionAcquireeDomain" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="BusinessAcquisitionAxis" xlink:to="BusinessAcquisitionAcquireeDomain" xlink:title="definition: BusinessAcquisitionAxis to BusinessAcquisitionAcquireeDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="BusinessAcquisitionAcquireeDomain_2" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="BusinessAcquisitionAxis" xlink:to="BusinessAcquisitionAcquireeDomain_2" xlink:title="definition: BusinessAcquisitionAxis to BusinessAcquisitionAcquireeDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_PowerSolutionsMember" xlink:label="PowerSolutionsMember" xlink:title="PowerSolutionsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="PowerSolutionsMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to PowerSolutionsMember" order="1.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/DebtDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LineOfCreditFacilityLineItems" xlink:label="LineOfCreditFacilityLineItems" xlink:title="LineOfCreditFacilityLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="LineOfCreditFacilityMaximumBorrowingCapacity" xlink:title="LineOfCreditFacilityMaximumBorrowingCapacity" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="LineOfCreditFacilityMaximumBorrowingCapacity" xlink:title="definition: LineOfCreditFacilityLineItems to LineOfCreditFacilityMaximumBorrowingCapacity" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LineOfCreditFacilityExpirationDate1" xlink:label="LineOfCreditFacilityExpirationDate1" xlink:title="LineOfCreditFacilityExpirationDate1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="LineOfCreditFacilityExpirationDate1" xlink:title="definition: LineOfCreditFacilityLineItems to LineOfCreditFacilityExpirationDate1" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LineOfCredit" xlink:label="LineOfCredit" xlink:title="LineOfCredit" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="LineOfCredit" xlink:title="definition: LineOfCreditFacilityLineItems to LineOfCredit" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:label="LineOfCreditFacilityCurrentBorrowingCapacity" xlink:title="LineOfCreditFacilityCurrentBorrowingCapacity" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="LineOfCreditFacilityCurrentBorrowingCapacity" xlink:title="definition: LineOfCreditFacilityLineItems to LineOfCreditFacilityCurrentBorrowingCapacity" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_PercentageOfCapitalStockOfForeignSubsidiariesGivenAsCollateralizedSecurityToLineOfCredit" xlink:label="PercentageOfCapitalStockOfForeignSubsidiariesGivenAsCollateralizedSecurityToLineOfCredit" xlink:title="PercentageOfCapitalStockOfForeignSubsidiariesGivenAsCollateralizedSecurityToLineOfCredit" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="PercentageOfCapitalStockOfForeignSubsidiariesGivenAsCollateralizedSecurityToLineOfCredit" xlink:title="definition: LineOfCreditFacilityLineItems to PercentageOfCapitalStockOfForeignSubsidiariesGivenAsCollateralizedSecurityToLineOfCredit" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd" xlink:label="LineOfCreditFacilityInterestRateAtPeriodEnd" xlink:title="LineOfCreditFacilityInterestRateAtPeriodEnd" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="LineOfCreditFacilityInterestRateAtPeriodEnd" xlink:title="definition: LineOfCreditFacilityLineItems to LineOfCreditFacilityInterestRateAtPeriodEnd" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InterestExpenseDebt" xlink:label="InterestExpenseDebt" xlink:title="InterestExpenseDebt" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="InterestExpenseDebt" xlink:title="definition: LineOfCreditFacilityLineItems to InterestExpenseDebt" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:label="DebtInstrumentBasisSpreadOnVariableRate1" xlink:title="DebtInstrumentBasisSpreadOnVariableRate1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="DebtInstrumentBasisSpreadOnVariableRate1" xlink:title="definition: LineOfCreditFacilityLineItems to DebtInstrumentBasisSpreadOnVariableRate1" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RepaymentsOfLinesOfCredit" xlink:label="RepaymentsOfLinesOfCredit" xlink:title="RepaymentsOfLinesOfCredit" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="RepaymentsOfLinesOfCredit" xlink:title="definition: LineOfCreditFacilityLineItems to RepaymentsOfLinesOfCredit" order="9.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases" xlink:label="LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases" xlink:title="LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases" xlink:title="definition: LineOfCreditFacilityLineItems to LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases" order="10.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_EffectiveLibor" xlink:label="EffectiveLibor" xlink:title="EffectiveLibor" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="EffectiveLibor" xlink:title="definition: LineOfCreditFacilityLineItems to EffectiveLibor" order="11.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_AvailableOfWithoutViolatingOurLeverageRatioCovenant" xlink:label="AvailableOfWithoutViolatingOurLeverageRatioCovenant" xlink:title="AvailableOfWithoutViolatingOurLeverageRatioCovenant" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="AvailableOfWithoutViolatingOurLeverageRatioCovenant" xlink:title="definition: LineOfCreditFacilityLineItems to AvailableOfWithoutViolatingOurLeverageRatioCovenant" order="12.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_DeferredFinancingCosts" xlink:label="DeferredFinancingCosts" xlink:title="DeferredFinancingCosts" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="DeferredFinancingCosts" xlink:title="definition: LineOfCreditFacilityLineItems to DeferredFinancingCosts" order="13.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_DeferredFinancingCostsAmortizationPeriod" xlink:label="DeferredFinancingCostsAmortizationPeriod" xlink:title="DeferredFinancingCostsAmortizationPeriod" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="DeferredFinancingCostsAmortizationPeriod" xlink:title="definition: LineOfCreditFacilityLineItems to DeferredFinancingCostsAmortizationPeriod" order="14.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebtByMaturityAbstract" xlink:label="LongTermDebtByMaturityAbstract" xlink:title="LongTermDebtByMaturityAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="LongTermDebtByMaturityAbstract" xlink:title="definition: LineOfCreditFacilityLineItems to LongTermDebtByMaturityAbstract" order="15.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:label="LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:title="LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:title="definition: LineOfCreditFacilityLineItems to LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" order="16.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:label="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:title="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:title="definition: LineOfCreditFacilityLineItems to LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" order="17.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:label="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:title="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:title="definition: LineOfCreditFacilityLineItems to LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" order="18.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:label="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:title="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:title="definition: LineOfCreditFacilityLineItems to LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" order="19.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:label="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:title="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:title="definition: LineOfCreditFacilityLineItems to LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" order="20.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:label="LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:title="LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:title="definition: LineOfCreditFacilityLineItems to LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" order="21.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebt" xlink:label="LongTermDebt" xlink:title="LongTermDebt" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="LongTermDebt" xlink:title="definition: LineOfCreditFacilityLineItems to LongTermDebt" order="22.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebtCurrent" xlink:label="LongTermDebtCurrent" xlink:title="LongTermDebtCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="LongTermDebtCurrent" xlink:title="definition: LineOfCreditFacilityLineItems to LongTermDebtCurrent" order="23.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="LongTermDebtNoncurrent" xlink:title="LongTermDebtNoncurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLineItems" xlink:to="LongTermDebtNoncurrent" xlink:title="definition: LineOfCreditFacilityLineItems to LongTermDebtNoncurrent" order="24.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LineOfCreditFacilityTable" xlink:label="LineOfCreditFacilityTable" xlink:title="LineOfCreditFacilityTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="LineOfCreditFacilityLineItems" xlink:to="LineOfCreditFacilityTable" xlink:title="definition: LineOfCreditFacilityLineItems to LineOfCreditFacilityTable" order="25.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeAxis" xlink:label="RangeAxis" xlink:title="RangeAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="LineOfCreditFacilityTable" xlink:to="RangeAxis" xlink:title="definition: LineOfCreditFacilityTable to RangeAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeMember" xlink:label="RangeMember" xlink:title="RangeMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="RangeAxis" xlink:to="RangeMember" xlink:title="definition: RangeAxis to RangeMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeMember" xlink:label="RangeMember_2" xlink:title="RangeMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="RangeAxis" xlink:to="RangeMember_2" xlink:title="definition: RangeAxis to RangeMember_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MinimumMember" xlink:label="MinimumMember" xlink:title="MinimumMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RangeMember" xlink:to="MinimumMember" xlink:title="definition: RangeMember to MinimumMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MaximumMember" xlink:label="MaximumMember" xlink:title="MaximumMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RangeMember" xlink:to="MaximumMember" xlink:title="definition: RangeMember to MaximumMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LineOfCreditFacilityAxis" xlink:label="LineOfCreditFacilityAxis" xlink:title="LineOfCreditFacilityAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="LineOfCreditFacilityTable" xlink:to="LineOfCreditFacilityAxis" xlink:title="definition: LineOfCreditFacilityTable to LineOfCreditFacilityAxis" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LineOfCreditFacilityLenderDomain" xlink:label="LineOfCreditFacilityLenderDomain" xlink:title="LineOfCreditFacilityLenderDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="LineOfCreditFacilityAxis" xlink:to="LineOfCreditFacilityLenderDomain" xlink:title="definition: LineOfCreditFacilityAxis to LineOfCreditFacilityLenderDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LineOfCreditFacilityLenderDomain" xlink:label="LineOfCreditFacilityLenderDomain_2" xlink:title="LineOfCreditFacilityLenderDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="LineOfCreditFacilityAxis" xlink:to="LineOfCreditFacilityLenderDomain_2" xlink:title="definition: LineOfCreditFacilityAxis to LineOfCreditFacilityLenderDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_NewSecuredCreditAgreementMember" xlink:label="NewSecuredCreditAgreementMember" xlink:title="NewSecuredCreditAgreementMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LineOfCreditFacilityLenderDomain" xlink:to="NewSecuredCreditAgreementMember" xlink:title="definition: LineOfCreditFacilityLenderDomain to NewSecuredCreditAgreementMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="CreditFacilityAxis" xlink:title="CreditFacilityAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="LineOfCreditFacilityTable" xlink:to="CreditFacilityAxis" xlink:title="definition: LineOfCreditFacilityTable to CreditFacilityAxis" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="CreditFacilityDomain" xlink:title="CreditFacilityDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="CreditFacilityAxis" xlink:to="CreditFacilityDomain" xlink:title="definition: CreditFacilityAxis to CreditFacilityDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="CreditFacilityDomain_2" xlink:title="CreditFacilityDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="CreditFacilityAxis" xlink:to="CreditFacilityDomain_2" xlink:title="definition: CreditFacilityAxis to CreditFacilityDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LineOfCreditMember" xlink:label="LineOfCreditMember" xlink:title="LineOfCreditMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="CreditFacilityDomain" xlink:to="LineOfCreditMember" xlink:title="definition: CreditFacilityDomain to LineOfCreditMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="RevolvingCreditFacilityMember" xlink:title="RevolvingCreditFacilityMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="CreditFacilityDomain" xlink:to="RevolvingCreditFacilityMember" xlink:title="definition: CreditFacilityDomain to RevolvingCreditFacilityMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_TermLoanMember" xlink:label="TermLoanMember" xlink:title="TermLoanMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="CreditFacilityDomain" xlink:to="TermLoanMember" xlink:title="definition: CreditFacilityDomain to TermLoanMember" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_DelayedDrawTermLoanMember" xlink:label="DelayedDrawTermLoanMember" xlink:title="DelayedDrawTermLoanMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="CreditFacilityDomain" xlink:to="DelayedDrawTermLoanMember" xlink:title="definition: CreditFacilityDomain to DelayedDrawTermLoanMember" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_VariableRateAxis" xlink:label="VariableRateAxis" xlink:title="VariableRateAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="LineOfCreditFacilityTable" xlink:to="VariableRateAxis" xlink:title="definition: LineOfCreditFacilityTable to VariableRateAxis" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="VariableRateDomain" xlink:title="VariableRateDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="VariableRateAxis" xlink:to="VariableRateDomain" xlink:title="definition: VariableRateAxis to VariableRateDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="VariableRateDomain_2" xlink:title="VariableRateDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="VariableRateAxis" xlink:to="VariableRateDomain_2" xlink:title="definition: VariableRateAxis to VariableRateDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:label="LondonInterbankOfferedRateLIBORMember" xlink:title="LondonInterbankOfferedRateLIBORMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="VariableRateDomain" xlink:to="LondonInterbankOfferedRateLIBORMember" xlink:title="definition: VariableRateDomain to LondonInterbankOfferedRateLIBORMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FederalFundsEffectiveSwapRateMember" xlink:label="FederalFundsEffectiveSwapRateMember" xlink:title="FederalFundsEffectiveSwapRateMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="VariableRateDomain" xlink:to="FederalFundsEffectiveSwapRateMember" xlink:title="definition: VariableRateDomain to FederalFundsEffectiveSwapRateMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BaseRateMember" xlink:label="BaseRateMember" xlink:title="BaseRateMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="VariableRateDomain" xlink:to="BaseRateMember" xlink:title="definition: VariableRateDomain to BaseRateMember" order="3.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/DebtDetailsCalc2" />
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/RetirementFundAndProfitSharingPlanDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="DefinedBenefitPlanDisclosureLineItems" xlink:title="DefinedBenefitPlanDisclosureLineItems" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_EmployerMatchOfFirstOnePercentOfCompensationContributedByParticipants" xlink:label="EmployerMatchOfFirstOnePercentOfCompensationContributedByParticipants" xlink:title="EmployerMatchOfFirstOnePercentOfCompensationContributedByParticipants" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="EmployerMatchOfFirstOnePercentOfCompensationContributedByParticipants" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to EmployerMatchOfFirstOnePercentOfCompensationContributedByParticipants" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_PercentageOfParticipantContributionOne" xlink:label="PercentageOfParticipantContributionOne" xlink:title="PercentageOfParticipantContributionOne" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="PercentageOfParticipantContributionOne" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to PercentageOfParticipantContributionOne" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_EmployerMatchOfNextFivePercentCompensationContributedByParticipants" xlink:label="EmployerMatchOfNextFivePercentCompensationContributedByParticipants" xlink:title="EmployerMatchOfNextFivePercentCompensationContributedByParticipants" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="EmployerMatchOfNextFivePercentCompensationContributedByParticipants" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to EmployerMatchOfNextFivePercentCompensationContributedByParticipants" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_PercentageOfParticipantContributionTwo" xlink:label="PercentageOfParticipantContributionTwo" xlink:title="PercentageOfParticipantContributionTwo" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="PercentageOfParticipantContributionTwo" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to PercentageOfParticipantContributionTwo" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:label="DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:title="DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_DefinedContributionPlanMinimumEmployerContributionPercent" xlink:label="DefinedContributionPlanMinimumEmployerContributionPercent" xlink:title="DefinedContributionPlanMinimumEmployerContributionPercent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="DefinedContributionPlanMinimumEmployerContributionPercent" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to DefinedContributionPlanMinimumEmployerContributionPercent" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_DefinedContributionPlanEmployerContributionPercent" xlink:label="DefinedContributionPlanEmployerContributionPercent" xlink:title="DefinedContributionPlanEmployerContributionPercent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="DefinedContributionPlanEmployerContributionPercent" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to DefinedContributionPlanEmployerContributionPercent" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PensionAndOtherPostretirementBenefitExpense" xlink:label="PensionAndOtherPostretirementBenefitExpense" xlink:title="PensionAndOtherPostretirementBenefitExpense" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="PensionAndOtherPostretirementBenefitExpense" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to PensionAndOtherPostretirementBenefitExpense" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_SharesHeldInPlan" xlink:label="SharesHeldInPlan" xlink:title="SharesHeldInPlan" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="SharesHeldInPlan" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to SharesHeldInPlan" order="9.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract" xlink:label="DefinedBenefitPlanNetPeriodicBenefitCostAbstract" xlink:title="DefinedBenefitPlanNetPeriodicBenefitCostAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="DefinedBenefitPlanNetPeriodicBenefitCostAbstract" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to DefinedBenefitPlanNetPeriodicBenefitCostAbstract" order="10.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost" xlink:label="DefinedBenefitPlanServiceCost" xlink:title="DefinedBenefitPlanServiceCost" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="DefinedBenefitPlanServiceCost" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to DefinedBenefitPlanServiceCost" order="11.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost" xlink:label="DefinedBenefitPlanInterestCost" xlink:title="DefinedBenefitPlanInterestCost" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="DefinedBenefitPlanInterestCost" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to DefinedBenefitPlanInterestCost" order="12.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DefinedBenefitPlanOtherCosts" xlink:label="DefinedBenefitPlanOtherCosts" xlink:title="DefinedBenefitPlanOtherCosts" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="DefinedBenefitPlanOtherCosts" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to DefinedBenefitPlanOtherCosts" order="13.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:label="DefinedBenefitPlanNetPeriodicBenefitCost" xlink:title="DefinedBenefitPlanNetPeriodicBenefitCost" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="DefinedBenefitPlanNetPeriodicBenefitCost" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to DefinedBenefitPlanNetPeriodicBenefitCost" order="14.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract" xlink:label="DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract" xlink:title="DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract" order="15.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTaxAbstract" xlink:label="DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTaxAbstract" xlink:title="DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTaxAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTaxAbstract" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTaxAbstract" order="16.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax" xlink:label="DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax" xlink:title="DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax" order="17.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax" xlink:label="DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax" xlink:title="DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax" order="18.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax" xlink:label="DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax" xlink:title="DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax" order="19.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:label="PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:title="PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" order="20.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:title="ScheduleOfDefinedBenefitPlansDisclosuresTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="DefinedBenefitPlanDisclosureLineItems" xlink:to="ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:title="definition: DefinedBenefitPlanDisclosureLineItems to ScheduleOfDefinedBenefitPlansDisclosuresTable" order="21.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="AwardTypeAxis" xlink:title="AwardTypeAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:to="AwardTypeAxis" xlink:title="definition: ScheduleOfDefinedBenefitPlansDisclosuresTable to AwardTypeAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="AwardTypeAxis" xlink:to="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="definition: AwardTypeAxis to ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_2" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="AwardTypeAxis" xlink:to="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_2" xlink:title="definition: AwardTypeAxis to ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockCompensationPlanMember" xlink:label="StockCompensationPlanMember" xlink:title="StockCompensationPlanMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="StockCompensationPlanMember" xlink:title="definition: ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain to StockCompensationPlanMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="PensionPlansDefinedBenefitMember" xlink:title="PensionPlansDefinedBenefitMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="PensionPlansDefinedBenefitMember" xlink:title="definition: ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain to PensionPlansDefinedBenefitMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_NonDefinedRetirementFundMember" xlink:label="NonDefinedRetirementFundMember" xlink:title="NonDefinedRetirementFundMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="NonDefinedRetirementFundMember" xlink:title="definition: ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain to NonDefinedRetirementFundMember" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="StatementClassOfStockAxis" xlink:title="StatementClassOfStockAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:to="StatementClassOfStockAxis" xlink:title="definition: ScheduleOfDefinedBenefitPlansDisclosuresTable to StatementClassOfStockAxis" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain_2" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain_2" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="CommonClassAMember" xlink:title="CommonClassAMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="CommonClassAMember" xlink:title="definition: ClassOfStockDomain to CommonClassAMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="CommonClassBMember" xlink:title="CommonClassBMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="CommonClassBMember" xlink:title="definition: ClassOfStockDomain to CommonClassBMember" order="2.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/AccumulatedOtherComprehensiveIncomeDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:label="AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:title="AccumulatedOtherComprehensiveIncomeLossLineItems" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_ChangesInAccumulatedOtherComprehensiveLossByComponentRollForward" xlink:label="ChangesInAccumulatedOtherComprehensiveLossByComponentRollForward" xlink:title="ChangesInAccumulatedOtherComprehensiveLossByComponentRollForward" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="ChangesInAccumulatedOtherComprehensiveLossByComponentRollForward" xlink:title="definition: AccumulatedOtherComprehensiveIncomeLossLineItems to ChangesInAccumulatedOtherComprehensiveLossByComponentRollForward" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:title="AccumulatedOtherComprehensiveIncomeLossNetOfTax" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:title="definition: AccumulatedOtherComprehensiveIncomeLossLineItems to AccumulatedOtherComprehensiveIncomeLossNetOfTax" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax" xlink:label="OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax" xlink:title="OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax" xlink:title="definition: AccumulatedOtherComprehensiveIncomeLossLineItems to OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax" xlink:label="ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax" xlink:title="ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax" xlink:title="definition: AccumulatedOtherComprehensiveIncomeLossLineItems to ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="OtherComprehensiveIncomeLossNetOfTax" xlink:title="OtherComprehensiveIncomeLossNetOfTax" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="OtherComprehensiveIncomeLossNetOfTax" xlink:title="definition: AccumulatedOtherComprehensiveIncomeLossLineItems to OtherComprehensiveIncomeLossNetOfTax" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:label="AccumulatedOtherComprehensiveIncomeLossTable" xlink:title="AccumulatedOtherComprehensiveIncomeLossTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="AccumulatedOtherComprehensiveIncomeLossTable" xlink:title="definition: AccumulatedOtherComprehensiveIncomeLossLineItems to AccumulatedOtherComprehensiveIncomeLossTable" order="6.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="StatementEquityComponentsAxis" xlink:title="StatementEquityComponentsAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="AccumulatedOtherComprehensiveIncomeLossTable" xlink:to="StatementEquityComponentsAxis" xlink:title="definition: AccumulatedOtherComprehensiveIncomeLossTable to StatementEquityComponentsAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="EquityComponentDomain" xlink:title="EquityComponentDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementEquityComponentsAxis" xlink:to="EquityComponentDomain" xlink:title="definition: StatementEquityComponentsAxis to EquityComponentDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="EquityComponentDomain_2" xlink:title="EquityComponentDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="StatementEquityComponentsAxis" xlink:to="EquityComponentDomain_2" xlink:title="definition: StatementEquityComponentsAxis to EquityComponentDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember" xlink:label="AccumulatedTranslationAdjustmentMember" xlink:title="AccumulatedTranslationAdjustmentMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EquityComponentDomain" xlink:to="AccumulatedTranslationAdjustmentMember" xlink:title="definition: EquityComponentDomain to AccumulatedTranslationAdjustmentMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:label="AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:title="AccumulatedNetUnrealizedInvestmentGainLossMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EquityComponentDomain" xlink:to="AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:title="definition: EquityComponentDomain to AccumulatedNetUnrealizedInvestmentGainLossMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember" xlink:label="SupplementalEmployeeRetirementPlanDefinedBenefitMember" xlink:title="SupplementalEmployeeRetirementPlanDefinedBenefitMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EquityComponentDomain" xlink:to="SupplementalEmployeeRetirementPlanDefinedBenefitMember" xlink:title="definition: EquityComponentDomain to SupplementalEmployeeRetirementPlanDefinedBenefitMember" order="3.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/CommitmentsAndContingenciesDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LossContingenciesLineItems" xlink:label="LossContingenciesLineItems" xlink:title="LossContingenciesLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LossContingencyNumberOfDefendants" xlink:label="LossContingencyNumberOfDefendants" xlink:title="LossContingencyNumberOfDefendants" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LossContingenciesLineItems" xlink:to="LossContingencyNumberOfDefendants" xlink:title="definition: LossContingenciesLineItems to LossContingencyNumberOfDefendants" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LossContingencyDamagesAwardedValue" xlink:label="LossContingencyDamagesAwardedValue" xlink:title="LossContingencyDamagesAwardedValue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LossContingenciesLineItems" xlink:to="LossContingencyDamagesAwardedValue" xlink:title="definition: LossContingenciesLineItems to LossContingencyDamagesAwardedValue" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_DamagesCoveredThroughIndemnificationAgreement" xlink:label="DamagesCoveredThroughIndemnificationAgreement" xlink:title="DamagesCoveredThroughIndemnificationAgreement" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LossContingenciesLineItems" xlink:to="DamagesCoveredThroughIndemnificationAgreement" xlink:title="definition: LossContingenciesLineItems to DamagesCoveredThroughIndemnificationAgreement" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_NumberOfPatents" xlink:label="NumberOfPatents" xlink:title="NumberOfPatents" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LossContingenciesLineItems" xlink:to="NumberOfPatents" xlink:title="definition: LossContingenciesLineItems to NumberOfPatents" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LossContingenciesTable" xlink:label="LossContingenciesTable" xlink:title="LossContingenciesTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="LossContingenciesLineItems" xlink:to="LossContingenciesTable" xlink:title="definition: LossContingenciesLineItems to LossContingenciesTable" order="5.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LitigationCaseAxis" xlink:label="LitigationCaseAxis" xlink:title="LitigationCaseAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="LossContingenciesTable" xlink:to="LitigationCaseAxis" xlink:title="definition: LossContingenciesTable to LitigationCaseAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LitigationCaseTypeDomain" xlink:label="LitigationCaseTypeDomain" xlink:title="LitigationCaseTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="LitigationCaseAxis" xlink:to="LitigationCaseTypeDomain" xlink:title="definition: LitigationCaseAxis to LitigationCaseTypeDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LitigationCaseTypeDomain" xlink:label="LitigationCaseTypeDomain_2" xlink:title="LitigationCaseTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="LitigationCaseAxis" xlink:to="LitigationCaseTypeDomain_2" xlink:title="definition: LitigationCaseAxis to LitigationCaseTypeDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_SynqorIncMember" xlink:label="SynqorIncMember" xlink:title="SynqorIncMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LitigationCaseTypeDomain" xlink:to="SynqorIncMember" xlink:title="definition: LitigationCaseTypeDomain to SynqorIncMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_MolexIncMember" xlink:label="MolexIncMember" xlink:title="MolexIncMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LitigationCaseTypeDomain" xlink:to="MolexIncMember" xlink:title="definition: LitigationCaseTypeDomain to MolexIncMember" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLeasedAssetsLineItems" xlink:label="OperatingLeasedAssetsLineItems" xlink:title="OperatingLeasedAssetsLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LeasesAbstract" xlink:label="LeasesAbstract" xlink:title="LeasesAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="OperatingLeasedAssetsLineItems" xlink:to="LeasesAbstract" xlink:title="definition: OperatingLeasedAssetsLineItems to LeasesAbstract" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherCommitmentsAbstract" xlink:label="OtherCommitmentsAbstract" xlink:title="OtherCommitmentsAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="OperatingLeasedAssetsLineItems" xlink:to="OtherCommitmentsAbstract" xlink:title="definition: OperatingLeasedAssetsLineItems to OtherCommitmentsAbstract" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_OutstandingPurchaseOrdersRelatedToRawMaterials" xlink:label="OutstandingPurchaseOrdersRelatedToRawMaterials" xlink:title="OutstandingPurchaseOrdersRelatedToRawMaterials" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="OperatingLeasedAssetsLineItems" xlink:to="OutstandingPurchaseOrdersRelatedToRawMaterials" xlink:title="definition: OperatingLeasedAssetsLineItems to OutstandingPurchaseOrdersRelatedToRawMaterials" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_OutstandingPurchaseOrdersRelatedToCapitalExpenditures" xlink:label="OutstandingPurchaseOrdersRelatedToCapitalExpenditures" xlink:title="OutstandingPurchaseOrdersRelatedToCapitalExpenditures" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="OperatingLeasedAssetsLineItems" xlink:to="OutstandingPurchaseOrdersRelatedToCapitalExpenditures" xlink:title="definition: OperatingLeasedAssetsLineItems to OutstandingPurchaseOrdersRelatedToCapitalExpenditures" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:label="OperatingLeasesFutureMinimumPaymentsDue" xlink:title="OperatingLeasesFutureMinimumPaymentsDue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="OperatingLeasedAssetsLineItems" xlink:to="OperatingLeasesFutureMinimumPaymentsDue" xlink:title="definition: OperatingLeasedAssetsLineItems to OperatingLeasesFutureMinimumPaymentsDue" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfOperatingLeasedAssetsTable" xlink:label="ScheduleOfOperatingLeasedAssetsTable" xlink:title="ScheduleOfOperatingLeasedAssetsTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="OperatingLeasedAssetsLineItems" xlink:to="ScheduleOfOperatingLeasedAssetsTable" xlink:title="definition: OperatingLeasedAssetsLineItems to ScheduleOfOperatingLeasedAssetsTable" order="6.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CounterpartyNameAxis" xlink:label="CounterpartyNameAxis" xlink:title="CounterpartyNameAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfOperatingLeasedAssetsTable" xlink:to="CounterpartyNameAxis" xlink:title="definition: ScheduleOfOperatingLeasedAssetsTable to CounterpartyNameAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RepurchaseAgreementCounterpartyNameDomain" xlink:label="RepurchaseAgreementCounterpartyNameDomain" xlink:title="RepurchaseAgreementCounterpartyNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="CounterpartyNameAxis" xlink:to="RepurchaseAgreementCounterpartyNameDomain" xlink:title="definition: CounterpartyNameAxis to RepurchaseAgreementCounterpartyNameDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RepurchaseAgreementCounterpartyNameDomain" xlink:label="RepurchaseAgreementCounterpartyNameDomain_2" xlink:title="RepurchaseAgreementCounterpartyNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="CounterpartyNameAxis" xlink:to="RepurchaseAgreementCounterpartyNameDomain_2" xlink:title="definition: CounterpartyNameAxis to RepurchaseAgreementCounterpartyNameDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_PowerSolutionsMember" xlink:label="PowerSolutionsMember" xlink:title="PowerSolutionsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RepurchaseAgreementCounterpartyNameDomain" xlink:to="PowerSolutionsMember" xlink:title="definition: RepurchaseAgreementCounterpartyNameDomain to PowerSolutionsMember" order="1.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://belfuse.com/role/SubsequentEventsDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventLineItems" xlink:label="SubsequentEventLineItems" xlink:title="SubsequentEventLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:title="PaymentsToAcquireBusinessesNetOfCashAcquired" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SubsequentEventLineItems" xlink:to="PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:title="definition: SubsequentEventLineItems to PaymentsToAcquireBusinessesNetOfCashAcquired" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_ExpectedRemainingPaymentRelatingToAcquisition" xlink:label="ExpectedRemainingPaymentRelatingToAcquisition" xlink:title="ExpectedRemainingPaymentRelatingToAcquisition" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SubsequentEventLineItems" xlink:to="ExpectedRemainingPaymentRelatingToAcquisition" xlink:title="definition: SubsequentEventLineItems to ExpectedRemainingPaymentRelatingToAcquisition" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="BusinessCombinationAcquisitionRelatedCosts" xlink:title="BusinessCombinationAcquisitionRelatedCosts" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SubsequentEventLineItems" xlink:to="BusinessCombinationAcquisitionRelatedCosts" xlink:title="definition: SubsequentEventLineItems to BusinessCombinationAcquisitionRelatedCosts" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:label="ProceedsFromIssuanceOfLongTermDebt" xlink:title="ProceedsFromIssuanceOfLongTermDebt" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SubsequentEventLineItems" xlink:to="ProceedsFromIssuanceOfLongTermDebt" xlink:title="definition: SubsequentEventLineItems to ProceedsFromIssuanceOfLongTermDebt" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventTable" xlink:label="SubsequentEventTable" xlink:title="SubsequentEventTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="SubsequentEventLineItems" xlink:to="SubsequentEventTable" xlink:title="definition: SubsequentEventLineItems to SubsequentEventTable" order="5.0" t1:closed="true" t1:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="SubsequentEventTypeAxis" xlink:title="SubsequentEventTypeAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="SubsequentEventTable" xlink:to="SubsequentEventTypeAxis" xlink:title="definition: SubsequentEventTable to SubsequentEventTypeAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="SubsequentEventTypeDomain" xlink:title="SubsequentEventTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="SubsequentEventTypeAxis" xlink:to="SubsequentEventTypeDomain" xlink:title="definition: SubsequentEventTypeAxis to SubsequentEventTypeDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="SubsequentEventTypeDomain_2" xlink:title="SubsequentEventTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="SubsequentEventTypeAxis" xlink:to="SubsequentEventTypeDomain_2" xlink:title="definition: SubsequentEventTypeAxis to SubsequentEventTypeDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="SubsequentEventMember" xlink:title="SubsequentEventMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SubsequentEventTypeDomain" xlink:to="SubsequentEventMember" xlink:title="definition: SubsequentEventTypeDomain to SubsequentEventMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="CreditFacilityAxis" xlink:title="CreditFacilityAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="SubsequentEventTable" xlink:to="CreditFacilityAxis" xlink:title="definition: SubsequentEventTable to CreditFacilityAxis" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="CreditFacilityDomain" xlink:title="CreditFacilityDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="CreditFacilityAxis" xlink:to="CreditFacilityDomain" xlink:title="definition: CreditFacilityAxis to CreditFacilityDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="CreditFacilityDomain_2" xlink:title="CreditFacilityDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="CreditFacilityAxis" xlink:to="CreditFacilityDomain_2" xlink:title="definition: CreditFacilityAxis to CreditFacilityDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="belfb-20140630.xsd#belfb_DelayedDrawTermLoanMember" xlink:label="DelayedDrawTermLoanMember" xlink:title="DelayedDrawTermLoanMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="CreditFacilityDomain" xlink:to="DelayedDrawTermLoanMember" xlink:title="definition: CreditFacilityDomain to DelayedDrawTermLoanMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="RevolvingCreditFacilityMember" xlink:title="RevolvingCreditFacilityMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="CreditFacilityDomain" xlink:to="RevolvingCreditFacilityMember" xlink:title="definition: CreditFacilityDomain to RevolvingCreditFacilityMember" order="2.0" />
  </link:definitionLink>
</link:linkbase>