Pb(Zr, Ti)O₃ (PZT) is a piezoelectric material applied in a typical actuator and has been actively studied. However, in order to overcome the limitations of PZT, piezoelectric ceramics comprising mixed solid solutions of PZT with various relaxer electric materials have been studied. The Pb(Zn_1/3Nb_2/3)-Pb(Ni_1/3Nb_2/3)-Pb(Zr, Ti)O₃ (PZN-PNN-PZT) piezoelectric ceramic, known to have high piezoelectric constant and electromechanical coupling coefficient, was studied herein. The piezoelectric characteristics with various Zr contents (Zr/Ti ratios), PZN molar ratios, and sintering temperatures were compared. The piezoelectric properties of d₃₃＝580 pC/N and kP＝0.68 were obtained with the 0.1PZN-0.2PNN-0.7PbZr_0.46Ti_0.54O₃ composition sintered at 1,290℃.