This paper analyses the origin of flood disaster in the Taihu Lake Plain and historical development of the water conservancy works, examines the natural and anthropogenic changes of Taihu Lake drainage basin and its hydro logical consequences over the past 40 years.Comments are made on the planning and design of the water conservancy works since the 1980s.The hydrological changes and the associated floods in the coming decades are discussed, with a speciai concern about the major impacts of global sea-level rise on the storage and release capacity of flood water.It is pointed out that, on the basis of MThe Ten Major Water Conservancy Worksw, the principal target of future hydro-engineering works should be focused on the great improvement of floodwater pumping capacity during the period of high-water and of the net flood water release out of the Huang pu River within each tidal cycle by building the Wusong Sluice.Meanwhile, non-engineering measures should be taken to protect and fully exploit the storage capadty of floodwater in the drainage basin.