Abstract: Based on qualitative analysis and quantitative research,the factors affecting gas occurrence,which included geological structures,hydrological geology,burial depth and thickness of coal seams,lithology of roof and floor rocks,had been discussed.By using statistical methods,the regression equations of relationship among thickness of coal seams,thickness of overlying bedrock and gas content were gained and the significance of the regression equations were tested.The results show the hydrogeological condition is the main factor on the regional distribution characteristics of gas occuerence,and the other factors,including geological structure,thickness of coal seams and overlying bedrock,and lithology of roof and floor rocks,have greater influence on local distribution of coal seam gas in study area.