Abstract: In the process of water injection in the Bohai P Oilfield, many problems appeared, such as the imbalanced water absorption of injection wells, injection water breakthrough, uneven utilization of reserves, and understanding of the distribution of residual oil. In this paper, reservoir connection and its controlling factors for fluvial multilayer sandstone reservoirs were studied through analysis of the data concerning pressure, water flooding, sedimentology and reservoir distribution. The results suggest that for different types of sediments, the reservoir connection of the Guantao Formation is better than that of the Minghua Formation in general. For the sediments of same type, however, the connection is better in the reservoirs with wide distribution, verticallysuperimpositionand lacking of intercalations.