The solubility of CO2 and N2O in a physical solvent, n-dodecane [C.A. Registry No 124-18-5], has been measured at 40, 80 and 120 degrees C at pressures up to 9.6 MPa. The experimental results were correlated by the Peng-Robinson (1976) equation of state, and the interaction parameters, the Henry’s constants and the N2O analogy parameters were obtained.