Gas-liquid equilibrium (GLE) data for the binary systems of {CO + DMC} and {O-2 + DMC} were respectively measured at 298.15-313.15 K and at 2.0-9.0 MPa. The modified UNIFAC model proposed by Sander et al. [10] was employed to correlate the experimental and literature GLE data for the binary systems of {CO + DMC}, {O-2 + DMC} and {CO2 + DMC} in a wide range of temperatures and pressures. At the same time, the missing energy parameters u(nm) of the carbonate group -OCOO- with the group CO, O-2, CO2 and -CH3 in the modified UNIFAC model were determined. It is indicated that the calculated GLE data using the new UNIFAC parameters are consistent with the experimental GLE data in this work and in literature. The results of this work are necessary and helpful for the UNIFAC database, which not only extend the application field of the UNIFAC model, but also are useful for the design of reactor and separation apparatus in DMC production. (C) 2010 Elsevier B.V. All rights reserved.