Bagebei siver polymetallic deposit in Inner Mongolia locates on polymetallic metallogenic belt in mid-south section of Greater Khingan Mountains. After intensive study and analysis, the authors believe that in this area dome structure was formed by intrusion of developed magma, and postmagmatic mineral-bearing hydrothermal fluid will mineralize through filling and metasomatism in radial or ringlike fissures. The result from the pulse action of magma, polyphase mineralization is overlapped with each other, and magmatic pulse in later phase forms main metallogenic epoch. Concealed rock bodies in depth may form porphyritic deposit, and its exocontact forms lode deposition the whole, there would be a great prospecting potential in finding large-medium silver polymetallic deposit in this area.