Rotary piston engine is a new kind of engine, which is still under development. Based on the kinetic characteristic and the special structure, a valve track was established using high-order polynomial method under the requirement of maximum fullness coefficient. Rotor was fixed after applying a reverse motion on the mechanism. Cam profile was built by coordinate transformation. A 3-dimension model was built and then it was imported into ADAMAS in order to study its kinematics behaviors responding to a specified motion .And the result shows that the method we take is effective; the cam profile has a ideal fullness coefficient, a continual acceleration, no hard or soft impact, and it could easily satisfies the requirement of the design of valve train.