Abstarct: In this thesis, some of thermodynamic properties such as the Helmholtz free energy, internal energy, compressibility factor, and the second virial coefficient were calculated for mon-atomic fluids including argon, xenon and krypton in different thermodynamic regions. To this purpose, the Sutherland potential model as well as the hard-sphere radial distribution function were used to calculate the static structural factor. The calculated values for the tixtled thermodynamic properties obtained via the integral equation method compared with the evaluable experimental data in a wide range of temperature and density. The results obtained for internal energy were shown that used potential model is capable to predict internal energy accurately. Furthermore, the investigation of calculated results for compressibility factor and their comparison with the experimental data indicated that the presented model is in a good agreement with experimental values in wide range of temperature and density. In all cases, using effective intermolecular parameters including the molecular diameter and the well-depth of potential lead to an improved in the calculated results at various thermodynamic states. Finally, the temperature dependency of inter molecular parameters was investigated.