Indoor static experiments were conducted to investigate the kinetics and equilibrium processes of phosphorus(P)adsorption and desorption by sediments collected from the midstream of the Huaihe River. The results of the kinetics experiments showed that the kinetics process of the P adsorption and desorption could be divided into a fast stage and a slow stage, and that the fast stage occurred in the first 1. 5 hours, while the adsorption rate was about 16 times of the desorption rate. The results of the equilibrium experiments showed that the amount of the solid phase equilibrium absorption of P by sediments increased with the liquid phase P concentration, and the increasing speed was faster when the liquid phase P concentration was low, but gradually slowed when the liquid phase P concentration further increased. The amount of the solid phase equilibrium desorption of P by sediments increased with the increase of the amount of the solid phase equilibrium absorption of P. The amount of equilibrium adsorption and desorption of P by sediments per unit mass was 16% to 40% of the amount of equilibrium adsorption of P. The adsorbed P could not be completely desorbed, which indicated that the adsorption process and the desorption process were not reversible. There was a linear positive correlation between the P retention capacity by sediments and the amount of solid phase equilibrium adsorption of P by sediments per unit mass, and the retention rate of P by sediments was 0. 847 in the midstream of the Huaihe River.