Abstract: The Lishui-Jiaojiang Depression is an important petroleum exploration target in the East China Sea Basin,which remains in the early stage of petroleum exploration. In this paper, geological data and the abundance,type and maturity of organic matter of the Yueguifeng source rocks were analyzed. Based on the data, hydrocarbon generation and expulsion history is quantitatively reconstructed. The results show that the abundance of organic matter is rather high in the Yueguifeng source rock, the organic matter is mainly belonging to typesⅡ₁ and Ⅱ₂, and the source rock are matured and highly matured. It means that the Yueguifeng source rock has the ability to generate both oil and gas. The Yueguifeng source rocks have passed two times of hydrocarbon generation and expulsion. However, the history varies in different tectonic unit. In a word, the petroleum system in Yueguifeng Formation should be the major exploration target in the study area.