Abstract: Using gas adsorption test system, gas adsorption experiments were carried out for gas-fat coal, lean coal and anthracite at 303 K and 293 K. Based on lattice theory model and the adsorption test of coal at a certain temperature, the gas adsorption laws of coal under different temperature were predicted. The results show that the linear relationship between the free gas molecular density and the adsorption capacity in different metamorphic grade coals. The isothermal adsorption curves of different metamorphic grade coals are predicted by lattice theory model, and compared with the measured results of gas adsorption isotherm, both the trend and the quantitative results are very consistent, and the relative error is no more than 3.8 %.