The impact drive mechanism utilizes friction and impulsive force caused by rapid deformations of a piezoelectric element to generate movement. Most of the devices reported in the past are linear mechanisms. In this paper, a rotary mechanism is developed and its motion characteristic is investigated systemically. The rotational movement is estimated theoretically. In experiments, the relationships between the rotational velocity and frequency, amplitude, rise time of the driving voltage are measured. Besides, as an important factor to influence the piezo actuator's performance, the fatigue of the mechanism is discussed originally.