A kind of 4A zeolite, which was modified by magnesium chloride and aluminum chloride, was used to treatment phosphorus wastewater. The effect of several parameters on phosphorus removal was also investigated, including zeolite dosage, pH, phosphorus concentration and the adsorption time. The results showed that, under the conditions of pH 7, the amount of modified 4A zeolite 0.05g, reaction time 15min, room temperature, the removal efficiency of phosphorus with initial concentration 2mg/L reached 98%. The SEM analysis explained that crystalline structure of 4A zeolite has changed after modification, thus resulted in the improvement of adsorption capacity. What’s more, the phosphorus removal mechanism was also discussed.