Abstract: The deep and relatively high-quality clastic reservoir rocks in southern margin of Junggar basin are dominated by anisometric sandstone, medium-fine grained sandstone and very fine grained sandstone deposited in shore and delta front, with characteristics of high compositional and structural maturity, low matrix content, low diagenetic evolution degree, weak cementation and preferable reservoir quality. They are related to the high-energy depositional environment, long-term basic diagenesis, the early long-term burying -the late short-term deep burying, abnormal high pressure and the early cement-the late solution. It is concluded that the structural zones of the second and the third rows could be important areas for exploration in southern margin of Junggar basin. The advantaged reservoir bodies deposited in the high-energy envirojnment of lakeshore and delta front of Paleogene, Neogene, Cretaceous and Lower Jurassic are major targets of petroleum exploration in deep areas of the southern margin.

Key words: Junggar basin, southern margin, relatively high-quality deep reservoir, controlling factor, exploration target