For separation of the azeotropic mixture (dimethyl carbonate + ethanol) by extractive distillation, butyl butyrate, o-xylene, and cyclohexanone were chosen as the solvents. The binary vapor liquid equilibrium (VLE) data for the systems (dimethyl carbonate + butyl butyrate/o-xylene/cyclohexanone) were determined at 101.3 kPa. The van Ness method and pure component consistency test were adopted to verify the consistency of the measured isobaric VLE experimental data. Further, the measured experimental data were correlated by the universal quasi -chemical, nonrandom two -liquid, and Wilson thermodynamic models, and the binary interaction parameters for the three models were optimized. Meanwhile, the values of the root-mean -square deviation for the temperature and the vapor phase composition are less than 0.31 K and 0.0087, respectively.