Manyusha shoal, located in the Kou’an straight reach, is a main navigation obstacle in the lower reaches of the Yangtze River. Based on the evolution character in the recent period, it shows that the navigation obstacle character is closely related with the scale of Manyusha shoal. Higher and more integral the shoal is, better the navigation condition is. It is concluded that Manyusha shoal and the left and right deep pools produce much scouring-silting change, which is the main cause of the formation of the shoa1, Especially, the reduction of sediment coming from upstream will result in that the shoal is easy to be eroded, while hard to be deposit. So the navigation condition will be severe. Based on an analysis of the navigation obstructing features of the shoal section, this paper proposes the regulation idea which is to maintain the existing pattern of one pool of two slots, to increase and heighten the central bar and adjust the flow distribution of riffle and pool so as to increase the scouring capability of shallow areas and solve the problem of navigation obstruction at the Manyusha shoal of Kou’an straight reach.