-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 D2q4GZIeA9lSMng6kYcmvj/e72lbLEJ6xzXJG2hJVxvje3nD5DbNl2xVv5VV7SwO
 nPNysHIMN5ffmFETcLl4RQ==

<SEC-DOCUMENT>0001262063-05-000062.txt : 20050511
<SEC-HEADER>0001262063-05-000062.hdr.sgml : 20050511
<ACCEPTANCE-DATETIME>20050511173420
ACCESSION NUMBER:		0001262063-05-000062
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050509
FILED AS OF DATE:		20050511
DATE AS OF CHANGE:		20050511

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CHUNG NELSON
		CENTRAL INDEX KEY:			0001326821

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31830
		FILM NUMBER:		05821776

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		(213) 625-4749

	MAIL ADDRESS:	
		STREET 1:		CATHAY BANK
		STREET 2:		777 NORTH BROADWAY
		CITY:			LOS ANGELES
		STATE:			CA
		ZIP:			90012

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CATHAY GENERAL BANCORP
		CENTRAL INDEX KEY:			0000861842
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				954274680
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		777 N BROADWAY
		CITY:			LOS ANGELES
		STATE:			CA
		ZIP:			90012
		BUSINESS PHONE:		2136254700

	MAIL ADDRESS:	
		STREET 1:		777 NORTH BROADWAY
		CITY:			LOS ANGELES
		STATE:			CA
		ZIP:			90012

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CATHAY BANCORP INC
		DATE OF NAME CHANGE:	19930328
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2005-05-09</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000861842</issuerCik>
        <issuerName>CATHAY GENERAL BANCORP</issuerName>
        <issuerTradingSymbol>CATY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001326821</rptOwnerCik>
            <rptOwnerName>CHUNG NELSON</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>777 NORTH BROADWAY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90012</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Nelson Chung</signatureName>
        <signatureDate>2005-05-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----