Pb(Zn1/3Nb2/3)(0.20)(Zr0.47Ti0.53)(0.80)O-3　ceramics,　with　the　addition　of　0-1.0wt%　MnO2,　were　prepared　by　conventional　mixed-oxide　technique　in　a　wide　sintering　temperature　region　from　1050　to　1200　degrees　C.　Microstructural　and　compositional　analyses　of　these　specimens　have　been　carried　out　using　X-ray　diffraction　(XRD)　and　scanning　electron　microscope　(SEM).　The　effects　of　MnO2　dopants　and　the　sintering　temperature　on　the　piezoelectric　and　dielectric　properties　of　Pb(Zn1/3Nb2/3)(0.20)(Zr0.47Ti0.53)(0.80)O-3　ceramics　have　been　investigated.　Compared　to　higher　densified　temperature　of　1200　degrees　C　for　undoped　specimen,　the　specimens　with　the　MnO2　doping　content　above　0.2wt%　have　maximum　density　at　1100　degrees　C　sintering　temperature.　Simultaneously,　the　optimum　piezoelectric　properties　were　also　obtained　at　1100　degrees　C　for　Mn-modified　specimens.　The　values　of　electromechanical　coupling　factor,　k(p)　and　dielectric　loss,　tan　8　were　optimized　for　0.5　wt%　MnO2　doped　specimen　(k(p)　=　0.65,　tan　delta　=　0.2%),　while　the　mechanical　quality　factor,　Q(m)　was　maximized　for　1.0　wt%　MnO2　doped　samples　(Q.　=　1300).　In　other　words,　the　optimum　sintering　condition　was　found.　(c)　2005　Elsevier　B.V.　All　rights　reserved.