Ring/dot-type step-down piezoelectric transformer was manufactured by using Pb[(Mn$sub$1/3/Sb$sub$2/3)$sub$0.05/Zr$sub$0.475/Ti$sub$0.475/]O$_3$ ceramics, which have excellent high-power piezoelectric properties. The characteristics of step-down piezoelectric transformer as a function of load resistance at output terminal was examined. Voltage gain was greatly dependent on drive frequency and load resistance, and showed maximum voltage gain at the resonance frequency. The output voltage was linearly increased as the input voltage increased. Voltage gain of the step-down piezoelectric transformer with respect to input voltage was very stable when the load resistance was in the range of 50-500 $Omega$ .