Abstract: Gas emission was huge in fully mechanized caving face of Shigang Coal Mine, the problem of gas concentration exceeding limits threatened the safety production of this mine in initial mining period. Through analyzing the gas emission features in No.15109 fully mechanized caving face during initial mining period, it obtained that gas emission had a larger fluctuation in initial mining period, which was mainly caused by the activities of overlying coal and rock seams. Collapse of the direct roof and main roof led to a large number of gas emission of the adjacent seam in succession, it obtained the change law of ventilation gas volume, pumping gas volume of high level suction roadway and gas concentration of tail roadway in initial mining period. Gas concentration exceeding limits distance of tail roadway was 4.5~27.8 m.The gas emission features of No.15109 working face in Shigang Coal Mine in initial mining period also applied for other fully mechanized caving faces in the first mining area, and provided important parameters for the gas control in the initial mining period of working faces in other mining areas with the same overlying coal and rock seams.