Pb(Ni1/3Nb2/3)0.5(ZraTib)0.5O3+x%ZnO(PNN-PZT+x%ZnO,x=0.2,0.4,0.6,0.8) piezoelectric ceramics were prepared by the conventional solid-state reaction method. The effects of different ZnO contents on the microstructure, phase structure, dielectric and piezoelectric properties. The XRD analysis indicated that the pyrochlore phase occurred with increasing of ZnO content. The SEM analysis indicated that the grain boundary is unclearly in high ZnO content. The dielectric properties indicated that the optimum properties of this system ceramic were obtained with x=0.4 at the sintering temperature of 1 190 ℃ for 2 h .The main parameters of the ceramic are as follows:εr=5 596, tan δ=2.12%,d33=534 pC/N,kp=0.53.