Abstract: Current state and progress of studies of wear on micro-electro-mechanical systems (MEMS), particular in micro rotating machines, are summarized in detail. Various wear behavior of MEMS and micro rotating machines are introduced and effects of material properties, roughness, environments, loadings and working conditions on wear are briefed. Many kinds of wear models, analysis methods, testing method and experiment instruments are discussed. Furthermore, prospect is also provided concerning further work in MEMS and micro rotating machines.