Abstract: By GC and GC-MS analyses the biomarker characteristics of the early Cretaceous source rocks in the Jixi Basin are discussed. Some typical biomarkers can be used to determine the biologic source nature of the organic material, its maturity and depositional environment. It can be seen that the thermal evolution of the samples have reached maturation stage, and the thermal evolution of the coals is higher than the mud rocks. The mud rocks are mainly from aquatic organisms with high-grade biology input. The coals are mainly from terrigenous with abundant aquatic organisms input. In the area the coals are formed in weak oxidizing environment. The mud rocks deposited in reducing environment with more saline water, it is better for retention and invert of organic material.

Key words: Jixi Basin, Early Cretaceous, source rocks, biomarkers