Abstract: Based on the basic principles and research methods of sequence stratigraphy, a precious sequence stratigraphic analysis of the Triassic Lower Karamay Formation in Ba'er Zone of Northwestern Junggar Basin is made, using outcrops, drilling, logging, and seismic data thoroughly. The sequence stratigraphic framework of the studied area and its corresponding development model are established. The Lower Karamay Formation can be divided into one third-order sequence and two system tracts, namely, a transgressive system tract and regressive system tract. Generally the thickness of sequence and system tracts with local variation are stable. The main sedimentary facies are braided river, braided river delta, lacustrine, subfacies and mocrofacies. The sequence stratigraphic model of the zone is the one that can not define the first flooding surface, which belongs to the depression basin.

Key words: Junggar Basin, Ba'er Zone, sequence division, sequence stratigraphic framework, sequence stratigraphic model