-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 K7XjT9lFm/T8x/I/s2EJjzFRqZa9dLLNfn1S4pHt25tamdVx14VKgfPbenLmfpwg
 al8X8CUgoG6JEpGOzZFxLg==

<SEC-DOCUMENT>0000941138-07-000195.txt : 20071231
<SEC-HEADER>0000941138-07-000195.hdr.sgml : 20071231
<ACCEPTANCE-DATETIME>20071231145550
ACCESSION NUMBER:		0000941138-07-000195
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20071228
FILED AS OF DATE:		20071231
DATE AS OF CHANGE:		20071231

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:			BILBY  ELIZABETH T
		CENTRAL INDEX KEY:			0001231009

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13739
		FILM NUMBER:		071334238

	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>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-12-28</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001231009</rptOwnerCik>
            <rptOwnerName>BILBY  ELIZABETH T</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1 S. CHURCH AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>UE183</rptOwnerStreet2>
            <rptOwnerCity>TUCSON</rptOwnerCity>
            <rptOwnerState>AZ</rptOwnerState>
            <rptOwnerZipCode>85701</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Dividend equivalent rights</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-12-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>26.4</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>26.4</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16075.2</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Dividend equivalents (with respect to dividends declared by the issuer on its Common Stock) credited under the UniSource Energy Corporation Omnibus Stock &amp; Incentive Plan.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>C. David Lamoreaux, attorney in fact</signatureName>
        <signatureDate>2007-12-31</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----