High-pressure phase equilibrium data for the ternary mixtures consisting of room temperature ionic liquid, dimethyl carbonate (DMC) and carbon dioxide (CO2) were measured using an equilibrium apparatus equipped with a variable-volume view cell. The ionic liquid studied in this work is 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C-6-mim][Tf2N]. Solubility data of carbon dioxide (CO2) in the solvent mixtures of DMC and [C-6-mim][Tf2N] with various compositions are presented at pressures up to about 7 MPa and at several temperatures between 303.15 and 333.15 K. The CO2 solubility in the DMC + [C-6-mim][Tf2N] solvent mixture decreased as the ionic liquid content in the mixture increased, compared at the same pressure and temperature. The equilibrium pressure increased with the increase of the content of ionic liquid in the solvent mixture. (C) 2009 Elsevier B.V. All rights reserved.