Abstract: Based on the relationship survied between the level, the area, and the storage of Poyang Lake of 1954, 1957, 1961, 1965, 1967, 1976, and 1984, the shape parameters and its variabilities of Poyang Lake were analyzed, and the variabilties of the yearly maximum level were estimated to reveal the variabilities of water regime. The effects of the innings on the flood levels were researched by using the crossing storage routings of the typical years in order to estabilish the relationship between the effect of the flood level inning effects and the embanked areas reflecting the variabilities of flood innings with the innings. The areas restoring embanked areas to natural state were determined based on the relationship between the benefit of restoring embanked areas to natural state and the states of closing levee levels for large-and middle-size closing levees.