The Density, Isochoric Heat Capacity, Shear Viscosity and Thermal Conductivity of CO2 Gas in the Pressure Range of 1-50 Atm and 300 K Are Calculated based on a Five-Centre Potential Model Obtained from Ab Initio Calculations of the Intermolecular Potential of a CO2 Dimer. the Quantum Effects of the Intramolecular Motion Are Included in a Model by the Monte Carlo (MC) Method. Without using Any Experimental Data, the Present Model Achieves Excellent Agreements between the Calculated Thermophysical Properties and Experimental Data for All Simulated CO2 Densities Except the Highest One at 135 Kg/m3 (3 Mol/L). the Contributions of Potential to the Thermophysical Properties of the Moderate Dense CO2 Gas and their Dependence on Density Are Investigated in Detail. © 2010 Taylor and Francis.