略述了鄱阳湖围垦的简要历史和现状，分析了近５０年来洪水位的演变趋势，指出围垦使鄱阳湖面积和容积缩小，调蓄功能衰退，以致水情不断恶化，洪峰水位逐渐上升，高水位的出现频率明显加大，致灾洪水越来越频繁．在此基础上，将围垦对洪水位的影响进行了分析计算，得出了各典型年洪水在不同围垦背景下的围垦效应值 The brief history and present situation of reclamation of Poyang Lake are briefly described. The evolvement trend of the flood level in the past 50 years is analyzed. It is pointed out that reclamation reduces the area and volume of Poyang Lake, and the storage function declines. As a result, the water condition worsens, The frequency of occurrence of water level obviously increases, the flood disaster is more and more frequent. On this basis, the impact of reclamation on the flood level is analyzed and calculated, and the reclamation effect value of each typical flood in different reclamation background is obtained