An experimental apparatus was built for measuring the gas solubility at high temperature and pressure. An auxiliary system was developed to keep the system pressure constant while the liquid samples are withdrawn. Solubility of methane, carbon dioxide and nitrogen in ethylene glycol (EG) was determined experimentally at temperatures of 323.15, 373.15 and 398.15 K and pressures up to 40 MPa. SRK equation of state was used to calculate the phase equilibria for those polar asymmetric systems.