Abstract: The region between the Yangtze river and the Huaihe mentioned in the artile,is from the south of the old course of the Huaihe (now the abandoned channel of the Huanghe) to the north of the Yangtze river.The data obtained by drilling 4 meters deep in Gaoyou,Xinghua,Yancheng,Baoying,Huaian,and Jianhu,show that are two types of lacutrine deposits in the late Holocene:one is the lake of continental facies and the other,the lagoon deposit.With the help of the historic and local records,the author tries to describe the transition and thedevelopment of the lakes of this region in number,area and form.There are widely distributed shallow peat deposits at 0～7 meters below the surface of this region and 3～4 layers of natural gas bearing strata of 7～30 meters deep.These facts can be used as evidence of the transitions in the early and middly Holocene to prove the actual existence of the numerous lakes and marshes during that period.During Ⅱ94～Ⅰ885 when the Huanghe captured the Huaihe,the changes of the lake areas were more markedly influenced by man-made factors mainly in twoaspeots:one was the building of the dykes along the Huaihea against the Huanghe, which caused the lakes to join together and enlarge their areas.These lakes were easily silted up by the river deposits during the flood time.The other aspect was the policy of retaining the clear Huaihe water to wash the Huanghe bed and to supply water for the Grand Canal.As a result,the area of the lakes west of the Grand Canal was gradually reduced,and the lakes in the area of Lixiahe were speedily silted up.