A physical modeling of an actuator is very important from two points of view; the deep understanding of the operation to improve its performance and the design of the servo system to realize high performance system. We are now working for the modeling of a surface acoustic wave (SAW) motor which is driven by frictional force resulted in nano meters elastic high frequency vibration 10 MHz or much higher. In case of the SAW motor, the vibration amplitude is from several nano meters to 30 nm at most. The vibration amplitude is almost same as the elastic deformation caused by preload between a slider and stator. In the analysis model, the elastic deformation, stick and slip were considered. Quasi-static simulation was carried out successfully; it has been cleared that the effect of mass is negligible. Experimental results of a 9.6 MHz operation frequency SAW motor were compared to the simulation results. It was understood that smaller projection slider with a lot of projections has high contact surface stiffness, so that superior performances are obtained in speed and thrust. To build up a servo system, behaviour modeling is also being investigated from experimental data of the SAW motor. The behaviour model is represented using a block diagram. The analysis modeling and the behaviour modeling will be compared and hopefully in agreement in the future.