Abstract: As one of the major reservoir types in China, braided river reservoir has generally entered the high water-cut stage, and its efficient development is seriously restricted by the in-layer heterogeneity. Based on the core and well logging information of Guantao Formation in Kongdian Oilfield, the in-layer heterogeneity of braided river reservoir and its influence on remaining oil distribution are analyzed combined with the production and development data. The results show that the reservoir in the area is formed by braided channel and channel bar. The braided channel shows normal rhythm, with great physical difference and thin interlayer; while the channel bar is dominated by composite normal rhythm, with medium physical difference and thick interlayer. There is much remaining oil controlled by the interlayer of production well corresponding to channel bar. The remaining oil enriched area is easily formed in the upper interlayer of vertical deposit body, which has great developing potential.