Isobaric vapor-liquid equilibria (VLE) are experimentally measured for the binary systems of dimethyl carbonate (DMC)+ ethylene carbonate and methanol + ethylene carbonate at 101.325 kPa. The thermodynamic consistency of these experimental data is tested with an available statistic method. Interaction parameters of the carbonate group -OCOO-with the group -CH3, ACH, CH3OH and CH3COO- in UNIFAC model are determined using the experimental and literature VLE data. The results show that the calculated VLE data using the new UNIFAC parameters agree excellently with the experimental data in this work and in literature. These results are useful in the research on DMC and diphenyl carbonate synthesis by transesterification in design of reactor and distillation tower.