Abstract: The rubber dam is a kind of water-retaining structure which has the advantages of low head, thin shell, flexible body, simple structure, convenient construction and low cost. Landscaped watercourse has been formed after building the rubber dam, which is used to retain and make lakes. But the operation of the dam will cause sedimentation in the upstream reservoir. Therefore, reasonable operation of the rubber dam is needed so as to maintain an ideal reservoir storage capacity for a long time. In this study, sediment calculation is made for ten years design for water and sediment conditions by using MIKE software, and the simulation of bed evolution is conducted to study the sediment deposition of Taohuatan reach in the Chan River. A comprehensive survey is made to show the changes of the flow field, aggradation thickness of the bed surface, river gradient and the vertical morphology of the river bed profile. What can be concluded from the result is that: the equilibrium for scouring and siltation in the reservoir of Taohuatan can be reached at about the seventh year, and the siltation in the main channel reach is rather serious; the river bed profile at the broadening reach is slightly convex upward after the scouring and siltation are in the state of equilibrium on the whole; on the basis of the geometric characteristics, the effect of the incoming water and sediment, and the backwater effect of flowing from wide channel to narrow one, the entering sediment laden flow will decrease due to the sudden widening of the river, which will lead to the reduction of sediment carrying capacity of flow and flow energy, hence resulting in easier siltation, higher bed surface, and higher flood water level.