Abstract: Based on the data from 584 wild cats anđ the reconnaissance/survey results about recent sediments of the north-western margin in Junggar Basin, the sedimentary characteristics of its Triassic and Jurassic strata have been studied, on which appropriate sedimentation models layer by layer have been developed as follows:
Baikouquan formation of Lower Triassic(T₁) could be a sequence of arid iand/semiarid land—braided river—meander river—lake basin delta—lacustrine deposit; Karamay formation of Middle Triassic(T₂) could be a sequence of cliff fan of displacement—fan delta or braided delta—lacustrine deposit; Baijiantan formation of Upper Triassic (T₃) could be a sequence of fan delta—lake and lake—bottom fan deposit; while Badaowan formation of lower Jurassic (J₁) could be a sequence of humid fan—rudaceous/tophaceous braided stream—flood plain of the stream deposit.

Key words: Sedimentation model, Northwestern margin in Junggar Basin, Cliff fan of displacement, Humid fan, Braided river, Delta, Flood plain