Pb(Mn₁/₃Nb₂/₃)O₃-PbTiO₃-PbZrO₃ (PMnN-PZT) has been widely used in high powder devices, ie transformer, ultrasonic motor because of its high mechanical quality factor as well as electromechanical coupling coefficient. In manufacturing process, however, it involves serious problems, such as compositional change and environmental pollution due to the volatility of lead oxide during sintering process (1200-1300 °C). The low temperature fabrication of PMnN-PZT ceramic using a low melting point additive or ions having similar to piezoelectric ceramic as sintering aids can solve these problems. However there have been some reports on the drawback of sintering aids that they alter the piezoelectric properties of the based composition. In this study, the effects of ZnO content on firing temperature and piezoelectric properties of the low temperature sintered PMnN-PZT was investigated. ZnO was added in a range of 0-1Wt% and the samples were fired at 900, 950, 1000 and 1050 °C. Physical and piezoelectric properties of the samples were examined and compared to those of PMnN-PZT ceramic without additive. From the study PMnN-PZT ceramic sintered at 1000 °C with 0.25 Wt% ZnO showed good piezoelectric properties nearly close to the pure PMnN-PZT which was sintered at 1250 °C. The density, Qm, d₃₃ and kp of this sample were 7.74 g/cm³,1195,260 pC/N, 0.55. respectively.