For seeking a new method to solve the problem of eutrophication, we have made the experiments of removing phosphorus in eutropic water by use of mineral calcite. The results indicate that the mineral calcite can remove phosphorus from the solution, and that the initial phosphorus concentration may influence the efficiency of phosphorus removal. The dephosphorization rate is high when the initial phosphorus concentration is 5 mg/L, and phosphorus can be removed by 88.48%; the dephosphorization rate may reach 69.94% when the initial phosphorus concentration is 3 mg/L; at 1.2 mg/L initial concentration only 12.68% phosphorus can be removed. Increasing temperature can also raise the efficiency of phosphorus removal. The result of TEM shows that the Ca-P precipitation is not in crystalline state.