Abstract:Deformation mechanism map, i.e.plastic deformation map, is effective to predict the material deformation during processing, which is very important for basic research on material processing. The constructing method, applying conditions and characteristics for the four deformation mechanism maps are introduced, for example, Ashby, Langdon-Mohamed, Ruano-Wadsworth-Sherby and dislocation R-W-S, respectively. The deformation mechanism map is the basic theory for application on production.