Abstract: A lot of thermo-physical properties are needed in hydrodynamic and thermodynamic calculation of gas pipelines. The method and process of gaining each parameter and the method of compiling the program to calculate the properties are mainly discussed in this paper. And some corresponding calculating examples are provided. After analysis, example calculation and comparison, the conclusion that BWRS equation is accurate and can be applied widely in the thermo-physical property calculation of natural gas is drawn.