Abstract: The Triassic Karamay Formation in the Beisantai region, Junggar Basin, Xinjiang is divided, on the basis of seismic data and well logs, into two systems tracts. The emphasis in this study is placed upon the sedimentary facies in individual systems tracts and planar distribution of the sedimentary systems in the Karamay Formation. The construction of sedimentary facies maps may facilitate to the delineation of the favourable sandstone distribution, and thus to the further exploration of oil and gas in the Beisantai region, Junggar Basin.