Based on porosity, water absorption and firmness coefficient of No. 15 coal seam and geological data of mine field in Longdong Mine, the possibility of the coal seam watering was analyzed, the influencing factors were analyzed from the aspect of hydrogeology. The result showed that the water content was large, the effect of water injection in coal seam was not obvious affected by meteoric precipitation and surface, groundwater, water in goaf, the coal seam was considered as no water injection seam.