Abstract: The crude 0il of the southern Xingshugang district in Daqing oil field is of lower density, 1ower viscidity，lower colloid，high wax and lower freezing point，and belongs to the typical light oil type．It also has higher saturated hydrocarbon content，overall hydrocarbon content and higher saturated to aromatic hydrocarbon ratio，which indicates the input of original algae．The carbon number distribution of normal alkanes shows a range from Cl5 to C39 with a peak at nC22 or nC23．Moreover，the whole oil and its family group show a feature of light carbon isotopes．The crude oil is very rich in steranes and contains a few 4-methyl steranes．The C27 and C29 sterane compound concentrations and the C28 sterane compound concentrations are low，and the distribution of ，C28 and C29 steranes is"L"shaped．The pentacyclic triterpanes in the crude oil ale also plentifu1．They are mainly hopanes，novel hopanes and gammaceranes． The oil-source rock correlation indicates that the crude oil has the similar carbon isotope compositions，and the similar steranes，terpanes distribution with the mudstone of the Lower Qingshankou Formation in Sanzhao sag，which suggests that the crude oil in the study area was derived from the Lower Qingshankou Formation in Sanzhao sag．