In this study, in order to develop low temperature sintering piezoelectric actuator, Pb(Mg½W½)0.03(Ni⅓Nb⅔)x(Zr0.50,Ti0.50)1-x-0.03 (PMW-PNN-PZT) ceramic systems were fabricated using CaCo₃-Li₂Co₃ sintering aid and their dielectric and piezoelectric properties were investigated with the variation of PNN substitution. The piezoelectric actuator requires high piezoelectric constant d33 and high electromechanical coupling factor kp. At the PMW-PNN-PZT ceramics with 9mol% PNN substitution sintered at 900℃, the density, electromechanical coupling factor kp, dielectric constant, piezoelectric constant d33 and mechanical quality factor Qm showed the excellent values of 7.86 [g/㎤], 0.584, 1881, 485 [pC/N] and 76, respectively for piezoelectric actuator application.