The ways of P removal from eutrophic aquaculture water in the process of phytoremediation included plant absorption,root system adsorption,sediment adsorption(mainly including flocculation and deposition)and P volatilization(PH₃)under reductive state.In order to futher investigate the mechanism of P removal and clarify the ways of P removal from eutrophic aquaculture water by phytoremediation,we took Pistia stratiotes L.and Secale cereale L.which had higher P removal efficiency as experiment materials respectively in summer-autumn(high-temperature)seasons and winter-spring(low-temperature)seasons.The contribution ratios of these four ways of P removal in the total phosphorus(TP)removal from eutrophic aquaculture water were respectively studied through simulating ideal ecological phytoremediation system.The study results showed that both of the two ecological floating culture plants P.stratiotes L.and S.cereale L.have higher TP removal efficiency from eutrophic cultivated water,which both reach higher than 50%;And the two main ways of P removal by ecological floating culture plants are plant absorption and sediment adsorption whose contribution ratios respectively are 23%-58% and 27%-51% for TP removal;Second is root adsorption whose contribution ratio is 13%-28%;The lowest contribution ratio was observed in the track of P volatilization under reductive state whose contribution ratio is only lower than 1.5%,thus,this contribution in TP removal is very small and could be neglected.The results of this study can be considered as the preliminary research basis for using ³²P isotope tracer method for further careful in depth study of the movement of P in eutrophic aquaculture water.