Abstract: The characteristics of coal adsorbing and desorbing gas have important significance to prevent gas accidents and coal seam gas drainage technology. In this paper, the adsorption and desorption of coal at different temperature was studied quantitatively, and the permeability of coal sample was analyzed from microscopic view. The conclusions are as follows：the process of coal adsorbing and desorbing gas can be divided into three different stages, moreover, the desorption rate and temperature shows a logarithmic relationship; from 20 ℃ to 80 ℃, the porosity shows the trend of first increasing and then decreasing. The 60 ℃ is the best temperature of coal adsorbing and desorbing gas from the aspects of coal body desorption rate and permeability.