Abstract: The recent exploration of oil and gas in the south edge of the Junggar Basin shows that there is huge resource potential in this area. In this paper, the sequence stratigraphic theory based on base-level cycles is used to divide the Mesozoic and the Cenozoic strata of this area into five secular stratigraphic cycles, including LSC1.LSC2, LSC3, LSC4 and LSC5. The developing characters of these cycles are summarized. In the framework of cycles, the dist ribution of reservoirs and cap rocks and the developing characters of their assemblages are analysed. It is pointed out that the study st rata of this area mainly develop LSC5, LSC4, LSC2 and LSC1 four assemblages. Among them, LSC4 and LSC1 are the most favorable gas assemblages of reservoirs and cap rocks.Combined with oil-generating, tectonic and other pool-forming conditions, two favorable gas-accumulation belts in this area are suggested, i. e. the Shanqian gas-accumulation belt in the south edge whose major target stratum is the Jurassic and the Xihu-Manasi-Hutubi favorable gas-accumulation belt whose major target stratum is the Lower Tertiary.