A rotary stepping ultrasonic motor composite the futures of the modal shift ultrasonic motor and the self-correction ultrasonic motor was proposed in this paper. It has no cumulative errors in open-loop control. An operating pattern was used to avoid miss steps which presented usually in the self-correction ultrasonic motors

and ameliorate the conflict between the output force and the step span which is a disadvantage of the modal shift ultrasonic motors. The prototype runs steadily without miss-step on trial

and the stall torque

single-step angler displacement

and the error of one step are 0.0032Nm

7.5°

and0.6°.