Abstract: Starting from thermodynamics, a form of energy dissipation function is introduced, a method of establishing constitutive model of concrete is proposed, and parameters of the model are discussed. Eventually a concrete multi-axial constitutive relationship, yield criterion, failure criterion and plastic flow rule in actual stress space based on thermodynamics are derived. The method invokes fewer hypotheses and avoids supposing a plastic potential function. The obtained model accords with thermodynamics naturally, and is universally valid. Numerical simulation is in conformity with experiments.