Abstract: A study of Lucaogou source rock in Malang sag,Santanghu basin is made. The result shows that 1) primary origin of asphaltene as-sumes predominant distribution in which organic matter could mainly come from bio-degradation of thallophyte; 2) the biomarker composition in soluble organic matter appears to be of general feature of mixed sources from both terrigenous higher plant and microorganism (thallo-phyte),with abundant hydrogen composition; 3) the sample of source rock reflects the characters of macroscopic pyrolysis with higher oil threshold temperature and narrower major hydrocarbon generation zone, similar to the hydrocarbon generation pattern of Type I kerogen. In addition,this source rock organic matter contains considerable amount of primary lipids,with a certain of low maturation hydrocarbon-gener-ated potentials.

Key words: Santanghu basin, source rock, asphalt, biomarker, pyrolysis, geochemistry