This thesis, the author discusses the migration of gas in the goaf of full- mechanized mining working face and its characteristic, on the basis of data collecting from mine, the author analyze and summarize law in full-mechanized mining working face, which including the emission source of goaf,the proportion of gas emission rate from goaf , the law of gas flow and the distributing of gas concentration, the thesis also analyze some factor that affect the emission rate from goaf ,the main factor a...