Abstract: Junggar Basin, a part of T ianshan - Xingmong Hercynian gcosycline fold system, possesses a Presinian mid - massif. It was surrounded by circumferential geosydines from Devonian to Carboniferous Period. And because of transgression the original marine formation which is the source rock in deep was disposted on it. The basin rose and became continent since Permian Period. In early Perm ian Epoch ii became a multi - downfalling and uprising fault - subsided basin and posse-ssed alternating sequences of marine and nonmarine formations. From late Permian Epoch to Tertiary Period it became a large united continental depression basin.
This paper discussed that Junggar Basin is a best one of petroliferous basins in china owing to following four aspects: (1) multicycle sedimentation was good to the com bination of source rock, reservoir and cap rock; (2) that basin continued to submerge steadily for longtime was profitable to the generation and transdirection of hydrocarbon; (3) the paleouplifts were the direction of hydrocarbon migration; (4) regional structures controlled the structura models of oil gas traps.