The solubility of p-hydroxybenzoic acid (p-HBA) and o-hydroxybenzoic acid (o-HBA) in ethyl acetate expanded with CO2 were determined at 308.15 and 318.15 K in the pressure range from 2.0 to 8.5 MPa. Both the solubility of p-HBA and o-HBA in the liquid phase decrease with pressure, especially at the higher pressures. However, the solubility of o-HBA in the CO2 + ethyl acetate mixture is much higher than that of p-HBA under the conditions reported in this study. The CO2 mol fraction in the liquid phase was also investigated, which increased with pressure and decreased with temperature. Peng-Robinson equation of state was used to correlate the CO2 mol fraction and solubility of the two solutes in the liquid phase. (C) 2000 Elsevier Science B.V. All rights reserved.