A comprehensive geochemical analysis of the crude oil samples frorn the southem margin of Junggar basin helps to classify them into six basic types of three categories.They are oil from the Jurassic coal measure(type (一七))

and from lacustrine source rocks of the Permian(type (一四))

Cretaceous(type (一五))

and Eogene(type (九))

and mixed oils from the Jurassic and the Eogene(type V)

and from the Jurassic and the Eogene(type V).It is showed that different tectonic units from the east to the west have different types of oils.The type iv

type (一七)

and type V

are found in Fukang fault zones.The Qigu faulted-fold belts have similar oil types to those of the Fukang fault zones but with the additional type (一五).While the Huoerguosi-Manasi-Tugulu anticline and Sikeshu sag are relatively simple with the former contains mainly type (一四) and later harbors type (九) and type iv.According to the above oil-source analyses

it is suggested that the (一四)-type oil from the Cretaceous should be the source of oil in the study area.