The dependences of the second and third virial coefficients of water vapor on the H2O molecule vibrational states are calculated. The model intermolecular Stockmayer potential is used taking into account the dipole-dipole interaction between excited molecules. The strong dependence of virial coefficients on molecular concentration is found. In this case a bending vibrational mode is excited. This also results in significant variations of thermodynamic parameters of water vapor, whose molecules are excited to the bending vibrational states.