Dongliu waterway locates between Jiujiang in Jiangxi province and Anqing in Anhui province.It’s a straight river with multiple branches. The upper part of the waterway is divided into two branches by the Laohutan beach:The left one is called Laohutan north channel, and the right one is Donggang. In recent years, due to the development of Donggang, the condition of Laohutan north channel is gets increasingly bad. Based on the observational data,this paper analyzes the development reason of Donggang channel and points out that the upstream runoff and sediment change after the impoundment and operation of the Three Gorges Reservoir is the most important reason for the development of Donggang chanel,and the waterway regulation engineering implemented promotes the development of Donggang to a certain extent.This paper also predicts the future development of Donggang based on the geological data.The research achievements may serve as reference for the follow-up project ideas and designs of waterway regulation.