Abstract: The Cretaceous oil sand resources reside in the Fengcheng area, northwestern Junggar Basin. The present paper focuses, in terms of core and thin section examination, well logs and laboratory data, on the type, distribution and evolution of sedimentary microfacies and construction of the sedimentary model for the Cretaceous Qingshuihe Formation. Two depositional systems are recognized in the Cretaceous Qingshuihe Formation:braided delta and fan delta depositional systems. The delta front subaqueous distributary channel, braided channel bar and channel sandstones are favourable for the accumulation of oil sands. The results of research in this study may provide useful references to the future exploration and development of the Cretaceous oil sand deposits in the Fengcheng area.