Abstract: In order to analyze the quantitative influence of the moisture to the gas desorption law, the method combined with the simulation measurement and test and the theoretical analysis was applied to the simulation measurement of the gas desorption law for No.3 seam in Xinjing Mine under the conditions of the different ad sorption balanced pressure and the different moisture content.With the fting analysis on the experiment data, the influence coefficient of the moisture to the gas desor ption law was obtained and the verification and comparison of the moisture influence cofficient obtained was conducted.The experiment results showed that with the C orrection of the influence coefficient, the desorption curve and the desorption curve obtained from the experiment could be almost fit.Thus the influence cofficient coul d well describe the gas desorption law under the different moisture content.Finally the paper had a theoretical analysis on the moisture affected to the gas desorption la W