Abstract: A self developed gas permeability test device was applied to study the adsorption role affected to the gas permeability of the gas seam from the adsorpti on pressure, adsorption pressure difference and adsorption temperature, meanwhile, simulated and analyzed the variation law of the permeability with gas drainage.Th e results showed that the adsorption value of the same coal samples would increase and the permeability would reduce with the adsorption pressure increased.Under t he same adsorption pressure, with the adsorption temperature increased, the permeability would reduce.After the seam gas drained, the gas pressure would reduce, th e permeability improved, it was the same to the experiment law.