An adsorption potential function produced by the interaction between gas and solid skelecton is introduced and regarded as a factor for the stress and deformation of the solid skeleton especially for the swelling of the coal. A general form of the thermoelastic constitutive model of coal is given considering the adsorption of CO2. After the thermodynamic analysis of the constitutive relation

it is found that the adsorption potential affects the stress and deformation indirectly through remodeling the form of the heat transfer equation and changing the thermodynamic restriction condition. But it doesn’t change the form of stress-strain relation. A constitutive model can be built the moment that the free energy function and adsorption potential are given.