In this paper a simple equation has been used to prediction the surface tensions of Ionic liquids solution based on the thermodynamic definition of surface tension and the expression of Gibbs free energy is used, which is different from existing ones with respect to theoretical background and formulation. By using the Wilson equation to represent the excess Gibbs free energy, a two-parameter surface tension equation is derived for liquid mixtures. The model parameters obtained by correlating binary surface tension at one temperature can be used to predict surface tension at other temperatures with good accuracy. The average relative error obtained from the comparison of experimental and calculated surface tension values for 20 binary systems are less than 1%. Therefore, the model has good accuracy in comparison with other predictive equations
