-----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,
 QEBYEWEFz3JLj+fRSUmIRRqa3nBZSCpxym5ANCVcpqboc186hvs1hspchvzv/LpT
 p1ayuigGXZQxQleB7trc8A==

<SEC-DOCUMENT>0001092306-06-000049.txt : 20060130
<SEC-HEADER>0001092306-06-000049.hdr.sgml : 20060130
<ACCEPTANCE-DATETIME>20060130155024
ACCESSION NUMBER:		0001092306-06-000049
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060127
FILED AS OF DATE:		20060130
DATE AS OF CHANGE:		20060130

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MATSON DAVID I
		CENTRAL INDEX KEY:			0001186356

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-15081
		FILM NUMBER:		06561918

	MAIL ADDRESS:	
		STREET 1:		C/O UNIONBANCAL CORP
		STREET 2:		3151 E IMPERIAL HWY
		CITY:			BREA
		STATE:			CA
		ZIP:			92821

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			UNIONBANCAL CORP
		CENTRAL INDEX KEY:			0001011659
		STANDARD INDUSTRIAL CLASSIFICATION:	NATIONAL COMMERCIAL BANKS [6021]
		IRS NUMBER:				941234979
		STATE OF INCORPORATION:			CA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		400 CALIFORNIA STREET
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94104-1476
		BUSINESS PHONE:		4157652969

	MAIL ADDRESS:	
		STREET 1:		400 CALIFORNIA STREET
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94104-1476
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>matson4_ex.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-01-27</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001011659</issuerCik>
        <issuerName>UNIONBANCAL CORP</issuerName>
        <issuerTradingSymbol>UB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001186356</rptOwnerCik>
            <rptOwnerName>MATSON DAVID I</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O UNIONBANCAL CORP</rptOwnerStreet1>
            <rptOwnerStreet2>3151 E IMPERIAL HWY</rptOwnerStreet2>
            <rptOwnerCity>BREA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92821</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice Chairman &amp; CFO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-01-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>8528</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>67.91</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by trust</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17481.2569</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by 401(k)</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Matson Family Trust U/A 7-7-92</footnote>
        <footnote id="F2">Shares held in the Union Bank of California 401(k) Plan as of 12/31/05.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ JOHN H. MCGUCKIN, JR., Attorney-in-fact for Mr. Matson</signatureName>
        <signatureDate>2006-01-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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