Abstract: Biological marker hydrocarbons were separated from source rock extracts and crude oil samples of Song-Liao,Shan-Gan-Ning,Tarim and North China basins by LC and identified mainly by GC/MS and MIKE techniques. The fingerprints of some individual triterpanes can be used to differentiate various crude oils originated from different geological basins.The source rock/ crude oil correlation based on molecular level of triterpane compounds distribution can be used to trace the migration of oil from source to reservior bed. The degree of maturity for various crude oils can be characterized by some parameters based on the ratio of stereoisomer and compounds distribution of triterpanes.Furthermore,a degraded hopane type was discovered in a heavy paphthenic oil in North China area.The degraded hopane differs from the normal hopane by the fact that it has only one methyl groups attached at C-4.