Abstract: Kumtak swell is one of the five large swells of pre-Jurassic in Turpan depression of Tuha basin. Up to now, it is believed to be the most hydrocarbon-enriched ancient swell among the five swells. But it is unclear that the conditions and rules of hydrocarbon's generation and reservation as well as its exploration target, which restrict its hydrocarbon exploration progress. The past-year experiences show that continuously developed ancient swell controls not only distributions of source rocks and reservoir facies belt, but also the direction of hydrocarbon migration. The research shows that hydrocarbon accumulation pattern of pre-Jurassic is the structuralstratigraphic reservoirs with source bed in lower formations and reservoir bed in upper formations under the settings of lateral migrated sandstone and denudated stratigraphic traps, and that of Jurassic is the structural-lithologic reservoirs with the same way under the settings of lateral migration of unconformity and overlying stratigraphic traps.

Key words: Tuha basin, Kumtak swell, hydrocarbon accumulation, rule, mode