NewrareearthvanadatesYSrQ-xCaxV3O9-y（x=0.0,0.67,1.0,1.33and2.0）havebeensynthesizedbyanewsimplemethod.X-raypowderdiffractionresultsshowthattheyaremono-phase.Theybelongtoorthorhombicstructureandtheirlatticeconstantsarecalculated.TheresultsofweightgainsinTGcurvesshowthatthelowervalentvanadiumisoxidizedtohighervalentstateathighertemperature.Theoxygencontentsofnewcompoundsarecalculatedfromtheweightgains.BothV3+andV4+coexistinYSr2-xCaxV3O9-y.Thesecompoundsexhibitlowelectricresistivityatroomtemperature.
