Abstract: Microelectromechanical system (MEMS) technology makes it possible the moralization and integration of the products based on the material of silicon. This technology is divided into four categories: body, surface, metal and compound micromechanical processes. The basic technologies included in the micromechanical system are erosion, si-bond, multiplayer film sediment without stress, sacrifice layer, LIGA and the combined technologies based on them. The applications of micro-sensors, micro-machines, mechanism filter and resonant filters are presented, and the further development of technology is discussed. Key words: micromechanical system; micro-machining; application of MEMS