Abstract: The production and operation of LNG terminal are based on liquefied natural gas (LNG) and natural gas (NG) properties calculation. Although there are many foreign commercial softwares which can calculate the properties, most of them are expensive and complex. Therefore, BWRS equation as the theoretical basis, the properties calculation software is designed based on the Forcecontrol Ⅴ7.0 software platform which is simple and can meet the needs of LNG Terminal. By comparing the data of the actual operation in Dalian LNG Terminal, calculated data by Aspen Plus and by this software, relative errors about some typical properties have been received. Meanwhile, the reliability of the calculation has been verified with some examples. Results show that the software can provide fairly accurate calculation results of LNG and NG properties and can well meet the properties calculation needs of LNG Terminal.