Nano-ceramics possessed ascendant mechanical property and physical characteristics contrast with traditional engineering ceramics, and its machining with ultrasonic assistance has been considered one of the most efficient methods. In the present paper a novel ultrasonic grinding vibration device has been developed and the theoretical model of grinding force has been created for ultrasonic vibration grinding. The influences of grinding parameters on grinding forces were tested with self-designd acoustic system based on local resonance. According to the test data, the effect of depth of cut and wheel velocity on the grinding force with/without ultrasonic assistance was analyzed. Both in common and ultrasonic grinding the normal grinding force and tangential grinding force descend against the wheel velocity, while ascend along with the depth of cut. In any case the grinding force in ultrasonic grinding was not more that that in common grinding.