-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 Dh89EyrsySa5G+MT2v3Jo+58DhgK4k+e6dxb4VSvoI3FEY+5wJA+1s6vpUEr66HS
 DpUYOhNNA2fxU7DiQr5u0Q==

<SEC-DOCUMENT>0000097854-10-000006.txt : 20100311
<SEC-HEADER>0000097854-10-000006.hdr.sgml : 20100311
<ACCEPTANCE-DATETIME>20100311163231
ACCESSION NUMBER:		0000097854-10-000006
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100310
FILED AS OF DATE:		20100311
DATE AS OF CHANGE:		20100311

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Hajj Imad
		CENTRAL INDEX KEY:			0001376828

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-04682
		FILM NUMBER:		10674382

	MAIL ADDRESS:	
		STREET 1:		8155 T&B BOULEVARD
		CITY:			MEMPHIS
		STATE:			TN
		ZIP:			38125

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			THOMAS & BETTS CORP
		CENTRAL INDEX KEY:			0000097854
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRIC LIGHTING & WIRING EQUIPMENT [3640]
		IRS NUMBER:				221326940
		STATE OF INCORPORATION:			TN
		FISCAL YEAR END:			1209

	BUSINESS ADDRESS:	
		STREET 1:		8155 T&B BOULEVARD
		CITY:			MEMPHIS
		STATE:			TN
		ZIP:			38125
		BUSINESS PHONE:		9012525000

	MAIL ADDRESS:	
		STREET 1:		8155 T&B BOULEVARD
		CITY:			MEMPHIS
		STATE:			TN
		ZIP:			38125
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-03-10</periodOfReport>

    <issuer>
        <issuerCik>0000097854</issuerCik>
        <issuerName>THOMAS &amp; BETTS CORP</issuerName>
        <issuerTradingSymbol>TNB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001376828</rptOwnerCik>
            <rptOwnerName>Hajj Imad</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>8155 T&amp;B BOULEVARD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MEMPHIS</rptOwnerCity>
            <rptOwnerState>TN</rptOwnerState>
            <rptOwnerZipCode>38125</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Sr. V.P. Global Operations</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-03-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>4500</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>38.8467</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>23251</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>65099.532</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>401(k)</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Shares awarded pursuant to a restricted stock grant on January 31, 2007.  Shares vested on February 1, 2010.</footnote>
        <footnote id="F2">This transaction was executed in multiple trades at prices ranging from $38.841 to $38.851.  The price reported reflects the weighted average sale price.  The reporting person hereby undertakes to provide upon request to the Securities and Exchange Commission full information regarding the number of shares and prices at which the transaction was effected.</footnote>
        <footnote id="F3">Common stock units held in the Thomas &amp; Betts Company Stock Fund, an investment option in the Thomas &amp; Betts Corporation Employees' Investment Plan.  This information is based on a plan report as of February 1, 2010.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>W. David Smith, Jr.,  Attorney-in-Fact</signatureName>
        <signatureDate>2010-03-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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