The effects of MnO2 doping on the properties of lead antimony manganese zirconate titanate Pb(Mn1/3Sb2/3)0.05Zr0.47Ti0.48O3(PMSZT5) ceramics were studied. The crystallographic phase and microstructure of PMSZT5 + z% MnO2 ( z = 0～0. 7 in mass) ceramics were investigated by means of X ray diffraction and scanning electronmicroscopy. The results show that a pure perovskite structure is obtained after calcined at 900 ℃ for 2 h. With MnO2 increasing, the number of tetragonal phase decreases, and the morphotropic phase boundary correspondingly shifts to a rhombohedral phase. A well situated property of relative dielectric constant εT33/ε0 (1 560) , piezoelectric constant d33 ( 350 pC/ N) , planar coupling factor kp (0.63) are obtained for the composition of PMSZT5+0.1% MnO2 ceramics sintered at 1 240 ℃. Compared with the undoped composition, the temperature stability of fr,d31 and k31 have been improved. The Curie temperature moves toward lower temperatures with MnO2 increasing.