Abstract: Some effects on operating noise, speed, torque output and smoothing performance of ultrasonic motor, such as frictional materials, pressing force on the rotor, operating frequency and electric match were studied experimentally and theoretically in this paper. The analyses and experimental results based on a bending vibration mode ultrasonic motor showed that operating noise was related to not only friction materials but also other many factors. Moreover, it was discovered that intensity and main frequency of the noise varied with the pressure between rotor and stator.