Abstarct: Thermodynamic properties have a wide influence in fluid proces analysis and phase change proceses like Liquefaction of hydrocarbons. Therefore exact calculating of thermodynamic properties in different phases and specially in equilibrium state is so important. Measuring devices can measure some of properties, but they can't useful in other properties like internal energy, enthalpy, entropy and complex mixture properties. Therefore we have to use equations of states. Equation of state is the cheapest ways to determine thermodynamic properties. Therefore enormous of EOSs have been represented by scientists. Recently, statistical thermodynamic has been developed in determining thermodynamic properties on molecular basis. PC-SAFT is a customary equation of state in literature which was calculated in papers. In this study, thermodynamic properties have been calculated using PC-SAFT for pure components and mixtures. Calculations have been validated with experimental data in literature. Average Absolute Deviation (AAD) of this calculation is 0.9474 for density, 0.6141 for compression factor, 0.4358 for enthalpy, 0.3512 for entropy, 0.5500 for internal energy, 2.6961 for heat capacity in constant volume, 2.2690 for heat capacity in constant pressure, 4.5724 for speed of sound and 4.5881 for joul-thomson coefficient. This results show that PC-SAFT EOS has high accuracy calculation thermodynamic properties of simple and complex mixture like natural gas in different phases conditions. In this study we try to calculate thermodynamic properties in a wide temperature and pressure range (Specially at high pressure and low temperature). After we had found that our results of PC-SAFT are acceptable, we simulated a sample of natural gas Liquefaction cycle.