A new elastoplastic constitutive model is presented in the framework of continiuum irreversible thermodynamics. The Mohr-Coulomb criterion is adopted. There are three internal variables adopted in this model: plastic strain

isotropic scalar damage variable D which describes the character of damage. The new constitutive relations strictly satisfy the basic requirement of thermodynamically consistent theory. Numerical validation of the prposed constitutive model has been carried out at local level. Uniaxial compression of concrete specimen under various confining pressures has been simulated. Results indicate the effectiveness of the proposed model.