ThispaperdevelopsamodifiedTaitequationofstate(EOS)fortrans-decahydronaphthalenewithfourparametersA,B,V0andP0beingtreatedaslinearfunctionsoftemperature.Thecoefficientscontainedinthesefunctionsaredeterminedthroughfittingtheexperimentalcompressiondataintheliteraturebetween293Kand446Kandatpressuresfrom10to200MPa.Expressionsforthethermalexpansivity,isothermalcompressibilityandthermodynamicquantitiesarededucedandthenumericalresultsareanalyticallyderived.ThenumericalresultsshowthattheprecisionofthemodifiedTaitEOSdevelopedinthispaperissuperiortotheEOSintheliterature.