-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0001209191-09-022525.txt : 20090423
<SEC-HEADER>0001209191-09-022525.hdr.sgml : 20090423
<ACCEPTANCE-DATETIME>20090423171716
ACCESSION NUMBER:		0001209191-09-022525
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090422
FILED AS OF DATE:		20090423
DATE AS OF CHANGE:		20090423

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HOHN CHRISTOPHER
		CENTRAL INDEX KEY:			0001440704

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08022
		FILM NUMBER:		09767339

	MAIL ADDRESS:	
		STREET 1:		C/O THE CHILDREN'S INVESTMENT FUND MGMT
		STREET 2:		7 CLIFFORD ST
		CITY:			LONDON
		STATE:			X0
		ZIP:			W1S 2WE

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:			1226

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

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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CHILDREN'S INVESTMENT MASTER FUND
		CENTRAL INDEX KEY:			0001441079
		STATE OF INCORPORATION:			E9
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08022
		FILM NUMBER:		09767336

	BUSINESS ADDRESS:	
		STREET 1:		PO BOX 309GT UGLAND HOUSE
		STREET 2:		SOUTH CHURCH STREET, GEORGE TOWN
		CITY:			GRAND CAYMAN
		STATE:			E9
		ZIP:			BWI
		BUSINESS PHONE:		44 207 440 2330

	MAIL ADDRESS:	
		STREET 1:		PO BOX 309GT UGLAND HOUSE
		STREET 2:		SOUTH CHURCH STREET, GEORGE TOWN
		CITY:			GRAND CAYMAN
		STATE:			E9
		ZIP:			BWI

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CHILDREN'S INVESTMENT FUND MANAGEMENT (CAYMAN) LTD.
		CENTRAL INDEX KEY:			0001441080
		STATE OF INCORPORATION:			E9
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08022
		FILM NUMBER:		09767337

	BUSINESS ADDRESS:	
		STREET 1:		PO BOX 309GT UGLAND HOUSE
		STREET 2:		SOUTH CHURCH STREET, GEORGE TOWN
		CITY:			GRAND CAYMAN
		STATE:			E9
		ZIP:			BWI
		BUSINESS PHONE:		44 207 440 2330

	MAIL ADDRESS:	
		STREET 1:		PO BOX 309GT UGLAND HOUSE
		STREET 2:		SOUTH CHURCH STREET, GEORGE TOWN
		CITY:			GRAND CAYMAN
		STATE:			E9
		ZIP:			BWI

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Childrens Investment Fund Management (UK) LLP
		CENTRAL INDEX KEY:			0001362598
		STATE OF INCORPORATION:			X0
		FISCAL YEAR END:			0831

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08022
		FILM NUMBER:		09767338

	BUSINESS ADDRESS:	
		STREET 1:		7 CLIFFORD STREET
		CITY:			LONDON
		STATE:			X0
		ZIP:			W1S 2WE
		BUSINESS PHONE:		44 207 440 2330

	MAIL ADDRESS:	
		STREET 1:		7 CLIFFORD STREET
		CITY:			LONDON
		STATE:			X0
		ZIP:			W1S 2WE
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>c84227_4x0.xml
<DESCRIPTION>MAIN DOCUMENT DESCRIPTION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-04-22</periodOfReport>

    <issuer>
        <issuerCik>0000277948</issuerCik>
        <issuerName>CSX CORP</issuerName>
        <issuerTradingSymbol>CSX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001440704</rptOwnerCik>
            <rptOwnerName>HOHN CHRISTOPHER</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O THE CHILDREN'S INVESTMENT FUND</rptOwnerStreet1>
            <rptOwnerStreet2>MANAGEMENT (UK) LLP 7 CLIFFORD STREET</rptOwnerStreet2>
            <rptOwnerCity>LONDON</rptOwnerCity>
            <rptOwnerState>X0</rptOwnerState>
            <rptOwnerZipCode>W1S 2WE</rptOwnerZipCode>
            <rptOwnerStateDescription>UNITED KINGDOM</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001362598</rptOwnerCik>
            <rptOwnerName>Childrens Investment Fund Management (UK) LLP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>7 CLIFFORD STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LONDON</rptOwnerCity>
            <rptOwnerState>X0</rptOwnerState>
            <rptOwnerZipCode>W1S 2WE</rptOwnerZipCode>
            <rptOwnerStateDescription>UNITED KINGDOM</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001441080</rptOwnerCik>
            <rptOwnerName>CHILDREN'S INVESTMENT FUND MANAGEMENT (CAYMAN) LTD.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>PO BOX 309GT UGLAND HOUSE</rptOwnerStreet1>
            <rptOwnerStreet2>SOUTH CHURCH STREET, GEORGE TOWN</rptOwnerStreet2>
            <rptOwnerCity>GRAND CAYMAN</rptOwnerCity>
            <rptOwnerState>E9</rptOwnerState>
            <rptOwnerZipCode>BWI</rptOwnerZipCode>
            <rptOwnerStateDescription>CAYMAN ISLANDS</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001441079</rptOwnerCik>
            <rptOwnerName>CHILDREN'S INVESTMENT MASTER FUND</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>PO BOX 309GT UGLAND HOUSE</rptOwnerStreet1>
            <rptOwnerStreet2>SOUTH CHURCH STREET, GEORGE TOWN</rptOwnerStreet2>
            <rptOwnerCity>GRAND CAYMAN</rptOwnerCity>
            <rptOwnerState>E9</rptOwnerState>
            <rptOwnerZipCode>BWI</rptOwnerZipCode>
            <rptOwnerStateDescription>CAYMAN ISLANDS</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, $1.00 par value (Common Stock)</value>
            </securityTitle>
            <transactionDate>
                <value>2009-04-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>6542259</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>28.38</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4295690</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-04-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>4295690</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>29.52</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5150</value>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $28.00  to $29.00, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price  within the ranges set forth in footnotes (1) and (3) of this Form 4.</footnote>
        <footnote id="F2">The Children's Investment Fund Management (Cayman) Ltd., a Cayman Islands exempted company (&quot;TCIF&quot;) and The Children's Investment Fund Management (UK) LLP, an English limited liability partnership (&quot;TCIF UK&quot;) serve as management companies for The Children's Investment Master Fund, a Cayman Islands exempted company (the &quot;TCI Fund&quot;). Christopher Hohn is the managing partner of TCIF UK and the 100% owner of TCIF, and therefore is in a position to determine the investment and voting decisions made by the TCI Fund. The Reporting Persons disclaim beneficial ownership of any and all securities reported herein in excess of their respective pecuniary interest therein and this report shall not be deemed an admission that the Reporting Persons are the beneficial owners of such securities for purposes of Section 16 or for any other purpose. Mr. Hohn is a director of the Issuer.</footnote>
        <footnote id="F3">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.005  to $29.82, inclusive.</footnote>
        <footnote id="F4">Shares of Common Stock previously reported as an exempt payment pursuant to Rule 16b-3  to Mr. Hohn of director's fees and/or annual retainer in the form of Common Stock of the Issuer pursuant to the CSX Corporation Stock Plan for Directors. Such shares of Common Stock are held directly by Mr. Hohn for the benefit of the TCI Fund.</footnote>
    </footnotes>

    <remarks>TCIF UK, TCIF and the TCI Fund may be deemed to be directors by deputization by virtue of the fact that Mr. Hohn, the managing partner
of TCIF UK and the 100% owner of TCIF, serves on the board of directors of the Issuer.</remarks>

    <ownerSignature>
        <signatureName>/s/ Christopher Hohn</signatureName>
        <signatureDate>2009-04-23</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ The Children's Investment Fund Management (UK) LLP, by Christopher Hohn, Managing Partner</signatureName>
        <signatureDate>2009-04-23</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ The Children's Investment Fund Management (Cayman) Ltd., by David de Rosa, Director</signatureName>
        <signatureDate>2009-04-23</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ The Children's Investment Master Fund, by David de Rosa, Director</signatureName>
        <signatureDate>2009-04-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----
