Low temperature sintering of Pb(Zr,Ti)O-3-Pb(Fe2/3W1/3)O-3-Pb(Mn1/3Nb2/3)O-3 (PZT-PFW-PMN) quaternary piezoelectric ceramics were studied with the use of YMnO3 as sintering aid. The sintering aid improved the sinterability of PZT-PFW-PMN ceramics due to the effect of YMnO3 liquid phase. The effects of YMnO3 contents and sintering temperature on the phase structure, density, dielectric and piezoelectric properties were investigated. The results show that the sintering temperature can be decreased and the electrical properties can be maintained by the YMnO3 addition. The optimized properties were obtained by doping 0.30 wt.% YMnO3 and sintering at 1020 C, which are listed as follows: d(33) = 341 pC/N, K-p = 0.57, Q(m) = 1393, tan delta = 0.0053, T-c = 304 degrees C, P-r = 17.13 mu C/cm(2) and E-c = 11.15 kV/cm, which make this system be a promising material for multilayer piezoelectric actuator and transformer applications. (c) 2007 Elsevier Ltd. All rights reserved.