Supercritical carbon dioxide was used as the reaction medium for the transesterification of ethylene carbonate (EC) with methanol to produce dimethyl carbonate (DMC) with K2CO3 as the catalyst under pressure up to 30 MPa. The effects of the presence of supercritical CO2 and the pressure on the conversion of EC and the selectivity of DMC were investigated. From the experimental results, it was found that the selectivity of DMC could be enhanced when the reaction was pressurized with supercritical CO2, although the conversion of EC decreased. (C) 2003 Elsevier B.V. All rights reserved.