The eutrophication is closely related to the accumulation of phosphorus in surface water. Therefore, the removal of dissolved phosphorus in water is the key to reducing the risk of eutrophication. In the past 10 years, the utilization of rare earth elements as an agent for sewage dephosphorization has achieved good results. In this study, the capability of eight crystalline rare earth oxides (Y₂O₃, La₂O₃, CeO₂, Pr₆O₁₁, Nd₂O₃, Sm₂O₃, Eu₂O₃ and Dy₂O₃) for removing phosphorus was detected. The results show that La₂O₃ has the best phosphorus removal performance, followed by Pr₆O₁₁, Y₂O₃, Eu₂O₃, Nd₂O₃. Sm₂O₃ and Dy₂O₃ have weak effects. CeO₂ has no phosphorus removal capability at all. The kinetic behavior of phosphorus adsorption on the surface of rare earth oxides is more in line with the quasi-first-order reaction model. The adsorption isotherm is consistent with the Langmuir model. The experiment reflects the alteration of rare earth oxides after phosphorus removal and the variance of pH value in the liquid during the process of phosphorus removal. It is believed that the dephosphorization of using the rare earth oxide to remove phosphorus is mainly by adsorption. The precipitation induced by the dissolution of oxides also plays a role. In order to avoid the declining of the surface adsorption capacity caused by agglomerate of the rare earth oxides in the water, the authors loaded the micro-nano particles of the La₂O₃ on the surface of different clay minerals. This design has significantly improved the phosphorus removal capability of the rare earth oxides. The amount of absorbed phosphorus was increased by approximately 25%. The phosphorus removal performance of the three clay minerals with the same amount of La₂O₃ was not significant. The improvement of rare earth oxide particle dispersion by clay minerals might be the main reason for increasing the phosphorus removal capability.