A New statistical thermodynamic model of surface tension for liquid mixtures is developed by using Davis model.When molecular energy parameter is considered as temperature dependent

the calculation results of surface tension for one-component system have been greatly improved.The total average relative deviation for 29 different pure liquids is less than 1.0%.The surface tension for 22 binary liquid mixtures has been also predicted and correlated

and the calculation deviations are 5.48% and 1.95% respectively.Using the adjustable parameters obtained from relevant binary systems

this equation can predict the surface tension of multicomponent liquid mixtures with good accuracy.The calculation results show that the model proposed is reliable and convenient for engineering application not only for pure liquids but also for multicomponent systems.