Relaxor　ferroelectrics　of　0.5Pb(Zn1/3Nb2/3)O-3-0.5Pb(Zr0.47Ti0.53)O-3　(0.5PZN-0.5PZT)　near　the　morphotropic　phase　boundary　(MPB)　were　prepared　using　the　conventional　oxide　mixing　method.　The　influence　of　sintering　temperature　on　the　phase　transition　and　dielectrical　response　in　the　relaxor-ferroelectric-system　0.5PZN-0.5PZT　has　been　investigated.　X-ray　diffraction　analysis　indicated　that　the　phase　of　the　material　changed　from　an　initially　rhombohedral　structure　to　a　MPB　structure　and　then　a　tetragonal　structure　when　the　sintering　temperature　is　increased　from　900　to　1250　degrees　C.　The　corresponding　grain　size　is　enlarged　from　1.1　mu　m　for　predominantly　rhombohedral　to　2.5　mu　m　for　more　than　60%　tetragonal,　which　obeys　the　common　grain-growth　law.　The　dielectric　studies　revealed　that　the　indicator　of　the　degree　of　diffuseness　gamma　decreased　with　the　increase　of　the　sintering　temperature　from　900　to　1150　degrees　C,　indicating　that　the　dielectric　relaxor　behavior　was　weakened,　while　at　high　sintering　temperature　above　1250　degrees　C,　gamma　increased　subsequently,　which　was　attributed　to　the　Pb　vacancy　due　to　the　formation　of　a　pyrochlore　phase.　Raman　analysis　on　the　B-site　cation　order　correlates　well　with　the　dielectric　measurement　results.　(c)　2007　American　Institute　of　Physics.