Abstract: Yanqi basin, located in south Tianshan mountain belt, is a Meso-Cenozoic medium-small superimposed composite hydrocar-bon basin developed on Hercynian fold basement and Proterozoic crystalline basement. Tectonic evolution in it underwent four stages of Pa-leozoic basement formation, Mesozoic foreland basin development, Tertiary compressional and depressed basin development and Quaternarystrike-slip and uplifting. It is Yanshanian and Himalayan faulting that control configuration and scale of its depression and uplift. The struc-tural deformation is characterized by thrust nappe and strike-slip associated with a large number of local structures. Study shows that struc-tural evolution has a significant effect on formation of petroleum system,hydrocarbon reservoir preservation condition and hydrocarbon en-richment regularity.

Key words: Xinjiang, Yanqi basin, structural evolution, hydrocarbon accumulation, petroleum exploration