Saturated fractions from 17 oil samples and saturated and aromatic fractions of extracts from 53 samples have been analyzed using GC-MS techniques.It is concluded that:1.Crude oil recently found in Linyi Basin

Shandong Province

are deri-ved from source rocks of the 3rd member of the Shahejie Formation in the southern depression;2.The configuration of organic matters were changed greatly within a depthof 2

500m

accompanied by dehydrogenation and deakyl side chain reactions. The depth can be considered as the threshold of oil generation within this ba-sin

where the geotherm is approximately of 96.5℃;3.The ratio(17β(H)/Ts)of the stereoisomer of C

27

-trinorhopane is a quite sensitive parameter for the determination of the degree of maturity.The author has worked out a “MDRH” diagram

and some geological para-meters such as vitrinite reflectance and total hydrocarbon/organic carbon etc.are plotted on this diagram by coordinate system.With this diagram

the phaseof hydrocarbon expulsion and appropriate epth of oil generation can beidentified on the basis of maturity parameters.