A new transesterification for preparing ethyl methyl carbonate from dimethyl carbonate and diethyl carbonate was carried out in the presence of solid basic catalysts both in the liquid and the vapor phase. Among the catalysts examined, MgO is the most active catalyst. Basic properties of the solid catalysts were measured by temperature-programmed desorption of CO2. The results revealed that the moderately basic sites on the catalysts play a crucial role in catalytic performance.