Isobaric vapor-liquid equilibrium (VLE) at 101.3 kPa for methanol + 1-methyl-3-methylimidazolium dimethylphosphate ([MMIM][DMP]), dimethyl carbonate (DMC) + [MMIM][DMP] methanol + 1-ethyl-3-methylimidazolium diethylphosphate ([EMIM][DEP]), and DMC + [EMIM][DEP] binary systems, as well as the VLE for the methanol + DMC + [MMIM][DMP] and methanol + DMC + [EMIM][DMP] ternary systems are measured using a circulation VLE still. With the addition of ionic liquids into the azeotropic system of methanol + DMC, the relative volatility of DMC is enhanced, which shows a salting-out effect of ionic liquids. The azeotropic point disappears when the mole fraction of ionic liquids is above 0.15. The salting-out effect on the DMC produced by [MMIM][DMP] is stronger than that produced by [EMIM][DEP]. The equilibrium experimental data is well correlated by the electrolyte nonrandom two-liquid model. (C) 2013 Elsevier B.V. All rights reserved.