Hard and brittle materials have some significant characteristics such as high strength, high hardness and low density.However, just because of high hardness and brittleness, great damage and low efficiency are the dramatic problems for these materials when processed by traditional methods.By contrast, ultrasonic assisted grinding(UAG)possesses some advantages such as lower grinding force and better processing quality.These characteristics bring particular advantages for machining hard and brittle materials.Considering different vibration dimensions and location positions between vibration direction and grinding surface, grinding mechanisms and performances of different kinds of UAG are summarized.On the base of these analysis, study of ductile-regime grinding mechanisms, matching performance between ultrasonic vibration and grinding parameters are discussed for UAG of hard and brittle materials.In addition, future prospect about research areas worth paying more attention to during UAG is analyzed.