In order to investigate the patterns of adsorption of phosphorus by sediment under different hydrodynamic actions,the adsorption of phosphorus and the vertical distribution of phosphorus were investigated through experiments in an elongated annular flume. The effects of velocity,initial phosphorus concentration,and sediment concentration were investigated. The results show that the vertical distribution of velocity in the elongated annular flume matched the logarithm law. The concentration of soluble reactive phosphate was distributed unevenly along the depth,and the maximum value appeared in the middle of the depth. The adsorption pattern of phosphorus under different velocity conditions depends on the mass concentration of soluble phosphorus. The amount of adsorption per unit mass of sediment decreased as the velocity increased when the phosphorus concentration was low,while it increased when the phosphorus concentration was high. The adsorption amount of phosphorus per unit mass of sediment increased as the sediment concentration decreased or the initial phosphorus concentration increased. The first- order and second-order dynamic equations can be used to describe the adsorption behavior of sediment in the Huaihe River. With the deposition of suspended sediment,the phosphorus concentration increased to a maximum at 0. 25 h and then decreased.