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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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 PO3xp9BOjJbCcbYFwOa/Mw==

<SEC-DOCUMENT>0001246360-06-002596.txt : 20061103
<SEC-HEADER>0001246360-06-002596.hdr.sgml : 20061103
<ACCEPTANCE-DATETIME>20061103105141
ACCESSION NUMBER:		0001246360-06-002596
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20061101
FILED AS OF DATE:		20061103
DATE AS OF CHANGE:		20061103

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			GATX CORP
		CENTRAL INDEX KEY:			0000040211
		STANDARD INDUSTRIAL CLASSIFICATION:	TRANSPORTATION SERVICES [4700]
		IRS NUMBER:				361124040
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		500 W MONROE ST
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60661
		BUSINESS PHONE:		3126216200

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	GENERAL AMERICAN TRANSPORTATION CORP
		DATE OF NAME CHANGE:	19750722

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DAMMEYER RODNEY F
		CENTRAL INDEX KEY:			0001077650

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-02328
		FILM NUMBER:		061185150

	BUSINESS ADDRESS:	
		STREET 1:		676 NORTH MICHIGAN AVE
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60611
		BUSINESS PHONE:		3129436327

	MAIL ADDRESS:	
		STREET 1:		676 N. MICHIGAN AVENUE
		STREET 2:		#2800
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60611
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-11-01</periodOfReport>

    <notSubjectToSection16>false</notSubjectToSection16>

    <issuer>
        <issuerCik>0000040211</issuerCik>
        <issuerName>GATX CORP</issuerName>
        <issuerTradingSymbol>GMT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001077650</rptOwnerCik>
            <rptOwnerName>DAMMEYER RODNEY F</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>4350 LAJOLLA VILLAGE DRIVE, #980</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92122</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2006-11-01</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>431.9696</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>43.4</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11566.6635</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Includes 57.5456 shares acquired pursuant to a dividend reinvestment feature of the GATX Directors' Phantom Stock Plan (&quot;Phantom Stock Plan&quot;).</footnote>
        <footnote id="F2">Includes that portion of the quarterly payment of the annual directors' fee (374.424 shares) credited to an account established for each director under the Phantom Stock Plan which in each case will be settled in common stock upon the expiration of the director's service on the Board.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Lisa M. Ibarra, by Power of Attorney on behalf of Rod F. Dammeyer</signatureName>
        <signatureDate>2006-11-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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