Geochemical features of source rocks have great significance on resource evaluation and exploration target optimization in Fushan sag. Multiple geochemical parameters analysis and comparison of the source rocks in the Liushagang Formation of Fushan sag suggest that hydrocarbon source rocks in the 3^rd member of the formation developed in freshwater lakes，weak oxidation environments with high abundance of organic matter which is type Ⅱ₁-Ⅱ₂. They are high quality source rocks. The source rocks in the 2^nd member of the Liushagang Formation developed in freshwater or brackish water，weak oxidation or slightly deoxidization environments with higher abundance of organic matter which is mainly type Ⅱ₁.They are high quality and high abundance source rocks. The source rocks in the 1st member of the Liushagang Formation developed in freshwater，weak oxidation sedimentary environment with high abundance of organic matter which is type Ⅱ₂.They are secondary high quality source rocks. Source rocks of the Liushagang Formation entered into its oil generation threshold at the late depositional stage of the E_{2l1 Formation（about 38 Ma），reached the peak period of oil eneration at the early depositional stage of E³}w^{1（about 30 Ma），and entered into its gas generation threshold at the early depositional stage of N（about 20 Ma），and it is still in the stage of a large amount of hydrocarbon generation. At present，hydrocarbon-generating intensity of Bailian subsag is higher than that of Huangtong subsag. The geochemcial features of source rocks show that the lower petroleum system of Bailian subsag is the best in Fushan sag，and the exploration potential in the E2l31 and E2l2 Formation in Bailian is greater with better reservoir-seal assemblage.}