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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 Jb3T7rRyptwUtt/gUus8Hw==

<SEC-DOCUMENT>0000277948-03-000019.txt : 20030801
<SEC-HEADER>0000277948-03-000019.hdr.sgml : 20030801
<ACCEPTANCE-DATETIME>20030801161708
ACCESSION NUMBER:		0000277948-03-000019
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030103
FILED AS OF DATE:		20030801

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CSX CORP
		CENTRAL INDEX KEY:			0000277948
		STANDARD INDUSTRIAL CLASSIFICATION:	RAILROADS, LINE-HAUL OPERATING [4011]
		IRS NUMBER:				621051971
		STATE OF INCORPORATION:			VA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		500 WATER STREET
		STREET 2:		15TH FLOOR
		CITY:			JACKSONVILLE
		STATE:			FL
		ZIP:			32202
		BUSINESS PHONE:		9043593200

	MAIL ADDRESS:	
		STREET 1:		301 WEST BAY STREET
		STREET 2:		21ST FLOOR
		CITY:			JACKSONVILLE
		STATE:			FL
		ZIP:			32202

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GIFTOS P MICHAEL
		CENTRAL INDEX KEY:			0001203253

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08022
		FILM NUMBER:		03818315

	MAIL ADDRESS:	
		STREET 1:		CSX CORPORATION
		STREET 2:		901 E. CARY STREET
		CITY:			RICHMOND
		STATE:			VA
		ZIP:			23219
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
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<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType><periodOfReport>2003-01-03</periodOfReport>
    <issuer>
        <issuerCik>0000277948</issuerCik>
        <issuerName>CSX CORP</issuerName>
        <issuerTradingSymbol>CSX</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001203253</rptOwnerCik>
            <rptOwnerName>GIFTOS P MICHAEL</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>CSX TRANSPORTATION, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>500 WATER STREET</rptOwnerStreet2>
            <rptOwnerCity>JACKSONVILLE</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>32202</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Executive VP of Subsidiary</officerTitle></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common stock</value></securityTitle><transactionDate><value>2003-01-03</value></transactionDate><transactionCoding><transactionFormType>5</transactionFormType><transactionCode>G</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>522</value></transactionShares><transactionPricePerShare><footnoteId id="F4"/></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>20049.9976</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><na
tureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Common stock</value></securityTitle><transactionDate><value>2003-03-28</value></transactionDate><transactionCoding><transactionFormType>5</transactionFormType><transactionCode>G</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>694</value></transactionShares><transactionPricePerShare><footnoteId id="F4"/></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>19355</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Common sto
ck</value></securityTitle><transactionDate><value>2003-07-31</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>M</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>11977</value></transactionShares><transactionPricePerShare><value>21.25</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>31332</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Common stock</value></securityTitle><transactionDate><value>2003-07-31</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormTy
pe><transactionCode>S</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>11977</value></transactionShares><transactionPricePerShare><value>31.8123</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>19355</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeHolding><securityTitle><value>Common stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>2248.9152</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>401(k)</value>
<footnoteId id="F1"/></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeHolding><securityTitle><value>Common stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>10000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By wife</value></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeHolding><securityTitle><value>Common stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>46588.0378</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>Executive Stock Trust</value><footnoteId id="F2"/></natureOfOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><derivativeTable><derivativeTransaction><securityTitle><value>Employ
ee stock option-option to buy</value></securityTitle><conversionOrExercisePrice><value>21.25</value></conversionOrExercisePrice><transactionDate><value>2003-07-31</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>M</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>11977</value></transactionShares><transactionPricePerShare><footnoteId id="F5"/></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><footnoteId id="F3"/></exerciseDate><expirationDate><value>2010-04-26</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>11977</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>23953</value></sharesOwnedFollowingTransaction></post
TransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">By Trustee of CSX Tax Savings Thrift Plan.</footnote><footnote id="F2">By Trustee, CSX Corporation Executives' Stock Plan</footnote><footnote id="F3">Options become exercisable in one-third increments on April 27 in each of the years 2003, 2004, and 2005.</footnote><footnote id="F4">Gift to family member who does not share reporting person's household.</footnote><footnote id="F5">Employee stock options granted pursuant to CSX Omnibus Incentive Plan.</footnote></footnotes><remarks/><ownerSignature><signatureName>P. Michael Giftos by Rachel E. Geiersbach, Attorney in Fact</signatureName><signatureDate>2003-08-01</signatureDate></ownerSignature></ownershipDocument>

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