Abstract: Longkou coal mining area is one of the few mining areas around the east sea line,which is focus on E coal measures.It is indicated by production practice that the main coal seam of Longkou coal mining area contains a low content of gas,but the excavated spaces always contain high content of gas in various coal mines.In this paper,based on analysis of the geological structures and gas geological characteristics,the existing laws of coal gas and their control factors have been summarized systematically,and the distribution of coal gas in different coal mines and their hazard have been assessed,which have important instruction for security production for coal mines.