The prediction method had been presented for salt effect on vapor-liquid equilibria by solvation model. This model assumes that salt effect is caused by solvation and solvated solvent molecular cannot contribute to vapor-liquid equilibria. The model took into account the vapor pressure depression in mixed solvent. In this work, the solvation model was modified. The relation between solvation number in pure solvent + salt system and correlation error was confirmed. Solvation number was determined by using a new relation. As a result, the model was satisfactory applied for all binary solvents + salt systems. Furthermore, ternary solvents + salt system was predicted by using solvation number in pure solvent determined from binary solvents + salt system. Good accuracy was shown.