Abstract: It was a difficult problem to analyze and trace the exact value of light hydrocarbon mixtures such as liquefied petroleum gas (LPG) in petrochemical industry due to the difference of saturated vapor pressure of each component. In this paper, the gas and liquid reference material of LPG was prepared. Through comparing the filling quality and quantity value accuracy of two types of samples, the result showed that the LPG liquid reference material prepared by piston cylinder could ensure the actual phase consistency of sample analysis, and provide accurate analysis of the value and improve the using cycle of reference material.