Abstract: Braided channel bar and braided channel are important oil and gas reservoir sandbodies, which are characterized by rapid lateral variation, poor continuity and connectivity, strong reservoir heterogeneity and obvious differences of sandbody scale among different areas and different types. These features seriously constrain the development of the braided river reservoir. Based on the reservoir architecture theory, the paper quantitatively characterizes the architecture units of the braided river reservoir of the lower He-8 section (i.e. H8x) in Su36-11 EOR test area of Sulige gas field and analyzes the effective sandbody distribution. The result show that the width of a single braided channel ranges from 100 to 550 m, and the length and width of braided bars are 1 350~4 300 m and 480~1 950 m, respectively. Finally, based on the development scale and distribution of sedimentary microfacies units and combined with production performance data, the comprehensive evaluation of effective sandbodies indicates that channel bars and braided channels are distributed continuously in H8x1-3 and H8x2-3 so that they are considered as the most favorable areas and target horizons with high drilling rate of effective sandbodies. The channel bars in H8x1-2 and H8x2-2 have high effective sandbody drilling rate and island-like channel bars are favorable reservoir sandbodies. Gas may be discovered in only a few channel bars in H8x1-2 and H8x2-2 so that the risks to develop the 2 horizons will be the highest