Objectives: The purpose of this paper is to discuss the indicative significance of sedimentary environment and maturity, reveal the source of asphalt, and provide the basis for oil and gas exploration in the Qiangtang Basin.Methods:Based on analysis of saturated hydrocarbons chromatogram- mass spectrometry for bitumen extracts, the geochemical characteristics of the bitumen in Mayashan area were researched, as well as its indicator significance of sedimentary environment, thermal maturity and oil source were discussed, too.Results:The test results show that the n- alkanes in Mayashan bitumen show no obvious odd—even carbon dominance, the ratios of (nC21+nC22)/(nC28+nC29) are relatively high, while the ratios of Pr/Ph, Pr/nC17are obviously low, and C27—C28—C29ααα20R distributes in asymmetric “V” shape. The values of maturity parameters, such as Ts/Tm, C29ββ/(αα+ββ) and C2920S/(S+R) are relatively low,while the 4- methyl- sters are also widely detected. The GC—MS characteristics of saturated hydrocarbons show that the bituminous kerogen mainly derived from lower level marine hydrobiont, which are at low mature stage and formed in reducing environment with some salinity. Conclusion: The oil source correlation reveals that the biomarkers characteristics of Mayashan bitumen are consistent with those of the Xiali source rocks in terms of n- alkanes, terpanes and steranes, indicating that they have close genetic relationship.