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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 ADpTCovS8sRSZmyowDgQnP0aLryi5NWInbk0248gJ37rUFsv/fnxarGlukoC9OTT
 LuXX6rbNR6QfLu9pBAbPNA==

<SEC-DOCUMENT>0000277948-03-000090.txt : 20031103
<SEC-HEADER>0000277948-03-000090.hdr.sgml : 20031103
<ACCEPTANCE-DATETIME>20031103122235
ACCESSION NUMBER:		0000277948-03-000090
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031103
FILED AS OF DATE:		20031103

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GRASSI ROBERT J
		CENTRAL INDEX KEY:			0001237367

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08022
		FILM NUMBER:		03972081

	BUSINESS ADDRESS:	
		STREET 1:		C/O CSX CORP
		STREET 2:		500 WATER STREET 15TH FLOOR
		CITY:			JACKSONVILLE
		STATE:			FL
		ZIP:			32202
		BUSINESS PHONE:		9043593200

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
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType><periodOfReport>2003-11-03</periodOfReport>
    <issuer>
        <issuerCik>0000277948</issuerCik>
        <issuerName>CSX CORP</issuerName>
        <issuerTradingSymbol>CSX</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001237367</rptOwnerCik>
            <rptOwnerName>GRASSI ROBERT J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>CSX WORLD TERMINALS</rptOwnerStreet1>
            <rptOwnerStreet2>2101 REXFORD ROAD, SUITE 250 WEST</rptOwnerStreet2>
            <rptOwnerCity>CHARLOTTE</rptOwnerCity>
            <rptOwnerState>NC</rptOwnerState>
            <rptOwnerZipCode>28211</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>President &amp; CEO of Subsidiary </officerTitle></reportingOwnerRelationship></reportingOwner><derivativeTable><derivativeTransaction><securityTitle><value>Phantom Stock Units</value></securityTitle><conversionOrExercisePrice><footnoteId id="F1"/></conversionOrExercisePrice><transactionDate><value>2003-11-03</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>30.2483</value></transactionShares><transactionPricePerShare><value>31.82</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><footnoteId id="F2"/></exerciseDate><expirationDate><footnoteId id="F2"/></expirationDate><underlyingSecurity><underlyingSecurityT
itle><value>Common stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>30.2483</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1952.9082</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">1-for-1</footnote><footnote id="F2">Phantom stock units acquired under CSX 2002 Deferred Compensation Plan to be settled solely in cash with distribution to commence at termination of employment or the attainment of a designated age based on an election made by the participant at least 1 year prior to distribution.</footnote></footnotes><remarks/><ownerSignature><signatureName>Robert J. Grassi by Rachel E. Geiersbach, Attorney in Fact</signatureName><signatureDate>2003-11-03</signatureDate></ownerSig
nature></ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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