The acceleration of urbanization in the Taihu Basin leads to hydrological regime changing significantly in the Jiangnan Canal. Based onthe precipitation, water stage, water diversion and drainage, as well as net inflow into the Taihu Lake, the water stage variation characteristics andcauses were analyzed by using Mann-Kendall testing. The results show that: (1) The increasing trend of the annual highest water stage, monthlyaverage water stage in May and September in Changzhou is resulted from the increase of the net transferred water from Huxi region. The increasingtrend of the average water stage in May and September in Luoshe and Wuxi is resulted from the increase of net transferred water fromWuchengxiyu region, while the increasing trend of the average water stage in June, July and August may be resulted from floodway deficiency. Thesynchronous increasing trend of the water stage in Suzhou is influenced by the increasing amount of sluice water diversion as well as upstreamwater intake. (2) In accordance with the urbanization acceleration process over the Taihu Basin, the significant mutation points of water stage onthe Jiangnan Canal occurred from the late 1990s to early 21st century. Under the same precipitation condition, the water stage rise more afterurbanization acceleration, especially inWuxi.