Test analyses such as pyrolysis, soluble organic matter extraction, group component separation and GC-MS were conducted to 22 source rock samples and 28 crude oil samples from deep lacustrine facies of Funing Formation in Subei Basin. Source rocks stayed at the low maturity-mature stage (Ro:0.58%–0.71%), while crude oil stayed at the mature stage (Rc:0.71%–0.88%). The Pr/Ph values of samples in the research area ranged between 0.16 and 0.62. These samples could be classified as Sterane/Hopane>1 and Sterane/Hopane<1. For all the samples, the C29 Steranes content was high; had inverse “L” distribution in ααα20RC27-ααα20RC28-ααα20RC29 regular sterane; αα20R-Sterane played a dominant role; abundances of ββ- and 20S-Sterane were low. As for samples of Sterane/Hopane>1, G/C30H ranged between 0.63 and 2.56, and the Sterane isomerization was very low. As for samples with Sterane/Hopane<1, G/C30H ranged between 0.04 and 0.46 and the Sterane isomerization was higher than the former. Abnormal distribution of Sterane isomerization was rarely influenced by thermal dynamic effects and sources, but was mainly influenced by the sedimentary environment. A lot of references reported Sterane isomerization with abnormally high abundance under the high-salinity environment. However, the finding obtained by the research that the higher water salinity corresponded to the lower degree of Sterane isomerization was discovered for the first time. The C29 Sterane abundance was high and the C29/C27 regular sterane ratio was constant and would not vary with changes of environmental parameters and biological source parameters. Sterane content was not correlated with tricyclic terpene of algae sources, but was positively correlated with ETR of the aquatic organism source, while it had very good positive correlation with Gammacerane. In addition, samples with the high Sterane content had high abundance in Carotene, C24+alkyl-cyclohexane and C21+isoprenoid alkanes. Through profound analysis and reference survey, it is found that the abnormally high abundance of C29 Sterane of samples in the research area may be correlated with halophilic protozoon in salinized deepwater lakes.