A clear perception on the current and historic flood control situation in the midstream and downstream of the Yangtze River is of crucial significance for future regulation and protection. The construction of water conservancy projects is a dominant measure of improving the flood control situation; in the meantime, the adaption of river-lake relation to natural evolution also affects the flood control situation. In view of this, the changes in river-lake relation in different periods since the 1960s are analyzed, and their influences on flood control situation are simulated.Furthermore, the favorable effect of water conservancy projects, in particular, the Three Gorges Project and its upstream control reservoirs, on flood control situation is examined; hence the variation process of flood control situation in the midstream and downstream of the Yangtze River is obtained. In addition, measures to improve flood control capacity, inclusive of upgrading project system, and enhancing joint scheduling ability, are discussed.