Thestructure,CurietemperatureandmagnetostrictionofPr0.15Tb0.30Dy0.55Fe1.85Cx(x=0-0.1)compoundswereinvestigatedbyX-raydiffraction,avibratingsamplemagnetometerandastandardstraintechnique.AllthesamplesshowentirelyMgCu2-typeLavesphasestructure.ThelatticeparameterandCurietemperatureincreasewithCcontentincreasing.Themagnetostrictionathighmagneticfieldshowsmaximumvalueatx=0.05.