Abstract: Effect of CaCl_2 and CuCl_2 on vapor-liquid equilibrium of ethanol-isopropanolwater ternary system was examimed with an improved Ellis recirculation still at constan atmospheric pressure. A thermordynamic correlating model was proposed by a method in which salt effect parameter is combined with the UNIFAC equation. Comparison of the calculated values with the experimental data shows that the average absolute deviation of the vapor phase mole fraction is below 0.018 7. It proves that the model can be used in process design.