The azeotrope methanol and methyl acetate is involved in the industrial manufacturing process of vinyl alcohol which is made from vinyl acetate by alcoholysis with methanol. This work focused on a study of ionic liquid as a solvent in the extraction separation for this azeotropic mixture. The knowledge of liquidliquid equilibrium (LLE) is essential for the design of the extraction separation process. For this reason, LLE data for the ternary system {methanol + methyl acetate + 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP])} were measured at the temperatures T = (298.2, 313.2, and 328.2) K and atmospheric pressure. The consistency of the experimental LLE data was ascertained by using the Othmer-Tobias and Hand equations. Additionally, the experimental LLE data were compared with the correlated values obtained by means of the nonrandom two liquid (NRTL) model. The solute distribution ratios and selectivity values, derived from the experimental LLE data, were calculated and analyzed in order to evaluate the efficiency as a solvent in liquid extraction process. The experimental results show that [MMIM][DMP] can be used as a potential solvent for the separation of methanol and methyl acetate in the liquidliquid extraction.