The key of commercial successes of MEMS rests with computer aided methodology in the field of MEMS design and manufacture.The reason that causes MEMS design complexity and hardship is discussed.The hierarchy of MEMS CAD is introduced.The state of research in MEMS macro-modeling approaches at home and abroad are also introduced and summed up.The emphases are aimed at the MEMS devices compact-modeling（order-reduced modeling） methods and the macro-model’s representation.The two keystones in the nonlinear macro-modeling are the representation of the original system’s nonlinear characteristics and the realization of automatic model reduction.Some suggestions for the further researches are proposed