Abstract:There are pores in the gangue of coal seam, and it has the ability of adsorbing gas. In order to study the pore characteristics of coalbed gangue in Xinjing Coal Mine of Qinshui Basin, the experimental study on static adsorption of liquid nitrogen was carried out by selecting gangue from seam 8# and gangue from seam 15#. According to the experimental results, the specific surface area, pore diameter ratio and aperture in the pore structure characteristics of gangue in No. 8# coal seam and No. 15# coal seam in Xinjing Coal Mine are analyzed. The results show that the gangue in Xinjing 8# coal seam is mainly composed of micropores and small holes, which account for more than 92% of the total holes. The gangue of Xinjing 15# coal seam is mainly composed of micro hole, small hole and middle hole. The proportion of micro hole and small hole is 67%, and that of middle hole is about 32%. The size of micropore and pore size has a strong correlation with the specific surface area and adsorption capacity.