Liquid-liquid phase equilibria for ternary systems of water + (ethanolil-propanol) + 1-decyl-3methylimidazolium bis (trifluoromethylsulfonyl) imide ([Dmim][NTf2]) were measured at T = 298.15 K and atmospheric pressure. Influences of alcohols with different length of alkyl chain on the liquid-liquid equilibria were revealed by the distribution coefficient and selectivity of the alcohols. The phase diagrams for the ternary systems were classified as Treybal's Type I behavior. The experimental data of ternary liquid-liquid equilibria were correlated by the nonrandom two liquid (NRTL) and the universal quasi-chemical (UNIQUAC) models, in which the interaction parameters were optimized. The values of root-mean-square deviation between the experimental and the calculated data show that those models can correlate the experimental data of the studied systems with good accuracy. (C) 2016 Elsevier B.V. All rights reserved.