Selective melting is a powder bed based metal additive manufacturing processes, and capable of manufac-turing components with complex shapes and manipulating the material micro-structures and properties locally and globally. Computational modeling of the manufacturing processes provides valuable instructions to advance the technologies. This paper introduces the research progress in this regard. Firstly, the principle and characteristics of laser/electron beam selec-tive melting are introduced. The state-of-the-art of numerical modeling of the manufacturing processes is summarized. The multi-scale multi-physics models for electron beam selective melting will be presented in detail, which consist of (1) a mi-cro-scale electron-material interaction model; (2) meso-scale models of powder particles from being spread to being heated, melted and solidified; (3) a macro-scale model of part fabrication process.