To enhance high power characteristics for piezoelectric transformer, an alloy design approach in PZT base ceramic system was considered. Various Zr/Ti ratio compositions in 0.03Pb(Sb0.5Nb0.5)O3- 0.03Pb(Mn1/3Nb2/3)O3-(0.94-x)PbTiO3-xPbZrO3 (0.445x0.475 mol)[PSN - PMN - PZT] system were synthesized by the conventional bulk ceramic processing technique. To improve high power characteristics at their morphotropic phase boundary (MPB) composition of PSN-PMN-PZT system, various spectra of Zr/Ti ratio were systematically experimented, and their effects on the subsequent piezoelectric properties and dielectric properties for high power piezoelectric transformer application were investigated using an impedance analyzer and a laser vibrometer. Microstructure and phase information were characterized using X-ray diffractometer (XRD) and a scanning electron microscope (SEM). When the Zr/Ti ratios were 0.475/0.465, the mechanical quality factor and electromechanical coupling factor were shown to reach the maximum, indicating that this alloy design can be a feasible composition for high power transformer.