Abstract: Using the analytic results of soluble extracted materials by GC and MS-GC, the combination characteristics of saturated hydrocarbon and aromatic hydrocarbon in Members E2S4, E2S3 and E2S1 of the Dawangbei subsag were studied. The different depositional environments and organic matter input characteristics of these three sets of source rocks were revealed，and the biomarker methods to identify the source rocks were presented. The results showed that the source rocks from the Member E2s4 are characterized by lower Pr/Ph, C29-4-methyl steranes and rearranged steranes, high dinoflagellate steranes, abnormal C35 homohopanes, abnormally high gammacerane index, small amount of oleanane and high content of DBT chemical compound,which indicates that these source rocks were developed in hyperhaline, sulfureous and strongly reducing sedimentary environment,predominance of lower-level aquatic organisms and significant contribution of high-level plants in the mixed organic matter input. The source rocks from the Member E2S3 are marked with relatively high Pr/Ph, low C29- 4-methyl steranes, high rearranged steranes, normal homohopanes, abnormally low gammacerane index, lower oleanane and rare dinoflagellate sterane, which shows that these source rocks were formed in the brackish-water reducing environment, and lower aquatic organisms were dominated and some high-level plants were involved in the organic matter input. The source rocks from Member E2s1 are characterized by extremely low content of Pr/Ph, the lowest C28- 4-methyl steranes, relatively high dinoflagellate steranes, lower rearranged steranes,abnormal C33 homohopanes, high gammacerane index, low oleanane and high dehydroxylated vitamin E, which demonstrates that these source rocks were formed in the hyperhaline and strongey reducing sedimentary environment, and the low-level aquatic organisms were dominated in the organic matter input. The changes of the biomarkers maturity parameters of hydrocarbon source rocks with depth were analyzed, and the results indicate that the evolutions of maturity parameters in different formations were different, which were probably caused by the sedimentary burial history and sedimentary environments. Therefore, different criteria should be built to evaluate the maturity parameters of source rocks and oil.