Taihu Lake is one of the five Iargest fresh 1akes.Located at the center of Taihu Lake Basin and controls the flood situation of Taihu Basin The main flood period of Taihu Lake and Basin is determined by plum rain period, which normally starts on June ll and ends on July 20.After an-alyzing the plum rain period in history, the highest water level of Taihu Lake in heavier flooding years, inflow and outflow around Taihu Lake in the past 22 years.the flod situation of Taihu Lake has changed, which is influenced by precipitation distribution, discharge change, and the operation of main channels such as the Taipu River and the Wangyu River.The decrease of dis-charge of Taihu Lake is primarily resulted from the accretion and reclaimed Land in East Taihu Lake.Studying the operational rule of main channels, dredging the mouths of the Taipu River and the Wangyu River.and reinforcing of the Around Thu Dyke are main measures to control flods of Taihu Lake Basin.