-----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,
 S2Fir24+/jdwIBuFbJPgYHT/GvY5EvJfn0K4im6A6azjtEc3AM8K2fxbhSIZ4ZOd
 7XDvHoX7PRLOjmGNQxRz8g==

<SEC-DOCUMENT>0000941138-08-000164.txt : 20080909
<SEC-HEADER>0000941138-08-000164.hdr.sgml : 20080909
<ACCEPTANCE-DATETIME>20080909180403
ACCESSION NUMBER:		0000941138-08-000164
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080905
FILED AS OF DATE:		20080909
DATE AS OF CHANGE:		20080909

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			UNISOURCE ENERGY CORP
		CENTRAL INDEX KEY:			0000941138
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRIC SERVICES [4911]
		IRS NUMBER:				860786732
		STATE OF INCORPORATION:			AZ
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		ONE SOUTH CHURCH AVENUE
		STREET 2:		SUITE 100
		CITY:			TUCSON
		STATE:			AZ
		ZIP:			85701
		BUSINESS PHONE:		520-571-4000

	MAIL ADDRESS:	
		STREET 1:		ONE SOUTH CHURCH AVENUE, SUITE 100
		STREET 2:		P.O. BOX 711
		CITY:			TUCSON
		STATE:			AZ
		ZIP:			85702

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LARSON KEVIN P
		CENTRAL INDEX KEY:			0001231030

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13739
		FILM NUMBER:		081063687

	MAIL ADDRESS:	
		STREET 1:		1 S CHURCH
		STREET 2:		STE 1820
		CITY:			TUCSON
		STATE:			AZ
		ZIP:			85701
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-09-05</periodOfReport>

    <issuer>
        <issuerCik>0000941138</issuerCik>
        <issuerName>UNISOURCE ENERGY CORP</issuerName>
        <issuerTradingSymbol>UNS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001231030</rptOwnerCik>
            <rptOwnerName>LARSON KEVIN P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1 S. CHURCH AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 201</rptOwnerStreet2>
            <rptOwnerCity>TUCSON</rptOwnerCity>
            <rptOwnerState>AZ</rptOwnerState>
            <rptOwnerZipCode>85701</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP, CFO and Treasurer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock Units</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-09-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>9.27</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>30.16</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>9.27</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1179.61</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Credited as fully-vested dividend equivalents under the UniSource Energy Corporation Management and Directors Deferred Compensation Plan (the &quot;DCP&quot;) with respect to dividends declared by the Issuer on its Common Stock.</footnote>
        <footnote id="F2">Payable at the time or times elected by the reporting person under the DCP and subject to earlier payment in accordance with the DCP.</footnote>
        <footnote id="F3">Converts to common stock on a 1-for-1 basis.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Raymond S. Heyman, Attorney in Fact</signatureName>
        <signatureDate>2008-09-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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