Abstract: In this paper,based on the exprimental results of a testing flume model,a systematical study on sediment deposition caused by circulating flow in the cecum branch is made.Details on the model of deposition,the size of infiunce zone,the variation in size distribution of sediment depositions and the properties of riverbed deformed are discussed.The main factors which influence the sediment deposits are analysed,and a formula to estimate the sediment deposition rate in the closed thannel is also established.Finally,a project measure for control sediment deposits is presented.