Abstract: The Jurassic in Junggar basin and its fifeen peripheral basins is a conbination of sequence with fair hydrocarbon potential: middle and Lower Jurassic are considered to be the source rock and resetvoir. and Upper Jurassic as the reservoir and regional caprock. According to the nature of basement. these basins can be divided into two categories; intermediate massif basin. with old craton of the Presinian period as basement, and intramontane basin. with new craton of the Hercynian period as basement. The fo:mer are nostly an inherited basin. with various oil-bearing sequences and betler oil potential; and the latter are mostly a residual basin. with complex hydtocarbon condition. Lower Catboniferous in Junggar basin is onmetamorphic paralic facies. and Devorian is also nonmetamotphic except in verv few aleas. As a results. this sequence should be considered as the caprock rather than as the basement.

Key words: Junggar basin and its peripheral basin, Jurassic, Types of basin, Hydrocarbon potential, Nature of basement