INTRODUCTIONCalciumphosphatecements(CPC)overcomethepracticaldisadvantagesofblocksorgranuleslcanbehandledasapasteandsitinsitu.TheirstructureandcompositionclosetothatofHAPmakethembiocompatiblematerials.2Theconventionalcalciumphosphatecementhadsomeproblemssuchaslongsettingtime(30~60min)andlowcompressivestrength,etc.Inoursystem,anα-TCP/TTCPpowdermixturewasmixedwithwatercontainingcitricacidtocontrolthesettingtimeandcompressivestrength.Inthispaper,theeffectsofvariousconcentrationcitricacidsolutionsonthepropertiesofthecementarereported.