Coal bed methane accumulation is significant impacted by groundwater dynamic field. In the eastern part of the study area the coal reservoir is buried in shallow，groundwater runoff effect is relatively strong and the dissipation of CBM is easy. In southwest of study area coal reservoir is bur-ied deeply groundwater runoff from northeast(shallow position) to southwest (position)，which playa blocking role on upward diffusion of CBM. In this area the groundwater water level is low and ground water is in retention state，which is the favorable area of coal bed methane accumulation. The characteristics of groundwater chemistry also affect coalbed methane accumulation. The study shows that underground water retention area and high-salinity distribution is consistent this shows that eigher retention groundwater or weak force alternately groundwater are favorable hydrogeological condi-dons for coalbed methane accumulation reservoir.