Heat generation phenomena and the change of electromechanical properties of piezoelectric ceramics were measured during high-power vibration using samples with similar electromechanical coupling factors but different mechanical quality factors. The change of the electromechanical properties was separately discussed in terms of the temperature dependence and applied voltage dependence. The vibration velocities during high-power vibration were calculated using these two dependences, and were compared with the measured values. In addition to the electromechanical properties, the jump phenomena of the motional admittance circle around the resonant frequency were investigated using constant-voltage and constant-current driving methods.