Vapour-liquid equilibrium data in the carbon dioxide-ethyl propanoate system were measured isothermally at 303.15 K, 313.15 K, and 323.15 K at pressures ranging from 2 MPa to 9 MPa. The experimental data were fitted to the Soave-Redlich-Kwong equation of state in the modification of Graboski and Daubert with the mixing rules developed by Kwak and Mansoori. Maximum likelihood procedure was adopted and all variables were assumed to be subject to errors.