Phosphorus is an important nutrient element that affects the growth of algae. The sorption of phosphorus on the sediments plays an important role in its bio-geochemical cycle, with metal oxides such as alumina being one of the important active components for the process. The sorption behavior of phosphorus on two kinds of alumina (γ-Al₂O₃, amorphous alumina) was studied through batch methods. Both kinetics and thermodynamics of the process were investigated, as well as the effects of temperature, salinity, and pH of the medium on the process. The sorption kinetic curves could be described by a two-compartment first order equation, and the isotherms fit Freundlich equation well. The amorphous alumina has a larger specific surface area, and its sorption ability is stronger than that of γ-Al₂O₃. Based on the results of surface acid-base titration, the sorption behavior is also considered to be related to the surface acidity and alkalinity of the aluminum oxides. Compared with NaNO₃ medium, the sorption of phosphorus in seawater was weakened. The sorption capacity decreases with the increase of the ionic strength. pH significantly affected the sorption ability of the oxides with the maximum capacity at pH=5. Higher temperatures are favorable to the sorption progress, which is endothermic and spontaneous with entropy increasing. The difference in the thermodynamic parameters of the two alumina seemed unremarkable.