Abstract: In the eutrophic water, three month trial purification was conducted by reeds and cattails to remove the total nitrogen and total phosphorus exceeded 30 mg/L and 8 mg/L respectively. The results showed that the two plants had high removal effect on nitrogen and phosphorus, while the removal rate of reed was higher than that of cattail. Through controlling water coverage of aquatic plants and harvesting plants, we can effectively reduce nitrogen and phosphorus content in water.