Abstract: The permeability of coal is influenced by frame stress and pore pressure, as well as influenced by the adsorption deformation of the coal. In this paper, the relationship between permeability and the coal deformation can be obtained through the experimental study. The test results show that if the gas component and the confining pressure are the same, the relationship between strain and permeability submits to the shape of the V curve. The strain has a critical range, when the strain is larger then this range; the permeability changes little with the augment of strain, while the strain is less then this range, the permeability changes obviously. While the gas component is not same, in high strain conditions, permeability of carbon dioxide is slightly more than the nitrogen permeability, and this is different from the relationship of pore pressure and permeability change.