Abstract: Based on drill cores, well logs and seismic data, the Triassic in Zhongguai area in northwestern margin of Junggar basin was classified in sequence stratigraphy as four Class?3 sequences and seven system tracts, and high?resolution sequence stratigraphic framework was established by Class?4 sequence as basic stratigraphic unit. This framework includes the analysis of the space?time configuration of the depositional system and the revealing of the distribution rules of hydrocarbon reservoirs in exploratory areas. The study shows that the boundaries of the Class?3 sequence and Class?4 sequence are significant factors for controlling formations of lithologic traps in this area. The lithologic traps are mainly distributed near the Class?4 sequence pinch out and the surroundings of Well 297-Well Ke?021 in the slope of Zhongguai swell