PbZrO3-PbTiO3-Pb(Fe2/3W1/3)O3-Pb(Mn1/3Nb2/3)O3 quaternary piezoelectric ceramics with various YMnO3 contents were successfully prepared by conventional mixed-oxide method. The effects of YMnO3 contents and sintering temperature on the dielectric and piezoelectric properties were investigated. The results show that the sintering temperature can be decreased from 1 200 ℃ to 1 020 ℃ and the electrical properties can be improved by the YMnO3 doping. The optimized properties were obtained by doping 0.30% YMnO3 and sintering at 1 020 ℃, which are listed as follows: d33=341 pc/N, Kp=0.574, Qm=1 393， tan δ=0.005 3，Tc=304 ℃ and ρ=5.23×1010 Ωm. These parameters make this material be a good candidate for application in high power piezoelectric transformers.