Abstract: The construction of flood storage and detention areas is one of the important and fundamental hydraulic engineering for river basin floods prevention in China. At present, 98 national flood storage and detention areas, with a total area of 34 261 km², have been established, as well as a number of local flood storage and detention areas. In order to understand the conditions of land development and constructions of the national flood storage and detention areas in the past 20 years, the land use data collected both in 2000 and 2018 are employed to analyze the land use changes and construction land increases in the national flood storage and detention areas. In addition, two typical flood storage and detention areas are selected to analyze the impacts of the land use changes and the flood storage capacities. The Watarase flood detention area in Japan as a typical case abroad is chosen to analyze the elaborated construction and management mode. The results show that the national flood storage and detention areas have significant variations in land use during last 20 years with significantly reduced farmlands(about 99 515 hm²)and increased construction lands(about 95 257 hm²). The Haihe River Basin has the largest increase in construction land(about 62 727 hm²), followed by the Yangtze River Basin(about 18 355 hm²)and the Yellow River Basin(about 6 450 hm²). The largest increase percentage of the construction land area is the Haihe River Basin(5.73%). The analysis results of the two typical flood storage and detention areas show that the flood storage capacity still has the potential to be exploited as long as the increased construction lands are well planned. However, the disordered development and construction may increase the flood loss caused by flood storage, which will affect the use of flood storage and detention areas. According to the analysis of the Watarase flood detention area in Japan, if the flood detention area is planned and constructed scientifically, reasonably and orderly, it can not only store floods naturally without dispute, but also have multiple functions such as drainage, water purification, ecology, landscape, tourism and entertainment. However, the flood storage and detention areas in China are still insufficient in these aspects. The research results in this paper can provide a useful reference for strengthening the construction and management of flood storage and detention areas in China.