Abstract: In order to identify the migration transformation process of phosphorus in water body and sediments in Qixing wetland, the concentration and distribution of phosphorus in surface water and porewater were analyzed, the morphological distribution characteristics of phosphorus in sediments studied, and the diffusion flux of phosphorus in the sediment-overlying water interface measured. Pearson correlation analysis was used to distinguish the different forms of phosphorus in water body and sediments. The results showed that the spatial distribution characteristics of total phosphorus in water body and sediments were slightly different. The concentration of TP in water body and sediments was higher at the entrance of the Xixiao River and the Wanquan River, and the concentration in both of them was lower at the Yangchang River. At the same time, the concentration of TP in the mainstream at exports of the wetlands was lower. IP was the main form of TP in sediments, accounting for 68.27%-87.41%. The proportion order of various forms of phosphorus in IP was NaOH-rP> HCl-P> Res-P> NaOH-nrP> BD-P. The diffusion flux of phosphorus in sediment-overlying water interface was positive, and the results showed that the sediments were important sources of phosphorus in the overlying water. Pearson correlation analysis also showed that BD-P from sediments was one of important inputs of phosphorus in body water, and TP and IP in sediments were mainly controlled by NaOH-rP.