Abstract: A new mixing rule was proposed by combining the hard-sphere three-parameter equation of state and the excess Gibbs energy model. Vapor-liquid equilibria at low and high pressure for 28 strongly polar binary systems and 9 ternary systems were predicted by using binary interaction parameter at low temperature of the group contribution model, such as UNIFAC and modified UNIFAC model. The results show that the new model yields accurate predictions for the phase equilibria of mixtures with a wide range of temperature and pressure.