Abstract: There are three processes in assembly for MEMS: parts making, parts-aligning and parts bonding. Parts-aligning is the most important process; its detailed steps of virtual assembly in virtual environment and the corresponding kinematics are given in this paper. Towards virtual operation, the kinematics of parts bonding is given as well. A virtual reality experimental platform is built up and an experimental example of ’peg into hole’ is conducted as the simplified example of virtual assembly for stator and rotor of micromotor in virtual environment; Preliminary experiment shows that the kinematics of virtual assembly for MEMS in virtual environment is correct.