Abstract: The effects of Cr₂O₃ addition on the microstructure and piezoelectric properties of 0.2Pb(Zn_1/3Nb_2/3)O₃- Pb(Ti_0.5Zr_0.5)O₃ （PZN-PZT） ceramics were investigated.When the concentration of Cr₂O₃ is below 0.3wt%, Cr₂O₃ doping results in the phase transition from rhombohedral to tetragonal phase, the increase of tetragonal phase, and the increase of grain sizes and bulk densities. However, when the concentration of Cr₂O₃ is above 0.3wt%, Cr₂O₃ will inhibit the grain growth and decrease the densities. Cr₂O₃ doping makes the materials harder,ε_r decreases, while Q_m increases with the increase of Cr₂O₃ while the tanδ, k_p and d₃₃ exhibits a minimum or maximum value with the increase of Cr₂O₃ content. The most optimum piezoelectric properties can be obtained with the concentration of Cr₂O₃ 0.3wt%.