Abstract: It’s been 10 years since the Three Gorges Project (TGP) began to operate in June 2003. The hydrological regime, the channel erosion/deposition, and the river-lake relationship in the river downstream of the project has been changing. The variations of flow and sediment transport, erosion/deposition in the mainstream of middle Yangtze River and in the three flow diversion channels, river regime in the mainstream of middle Yangtze River, as well as river-lake relationship are briefly analyzed. The river-lake evolution in the middle Yangtze River predicted by the Changjiang (Yangtze) River Scientific Research Institute (CRSRI) via physical model tests and mathematical modeling are introduced. Comparison between the model predictions and prototype observations are presented. On this basis, the evolution and regulations of rivers and lakes after the joint operation of reservoirs in the upstream Yangtze River are further discussed. The results provide reference for the strategy, formulation and implementation of regulation measures for rivers and lakes.