Aquatic plants grow in water with photosynthesis and purify water quality as taking organic and inorganic matter in water. Polluted water in stagnant stream channel where nutritive salts load is great can be purified by activities of aquatic plants. Aquatic plants should be fixed to bed easily to plant and sustainable environment is needed. So in this study, Mattress/Filter system is suggested to plant aquatic plant in stagnant stream channel. In the result of study, coverage of Phragmites australis, Zizania latifolia and Typha angustifolia which planted in mattress was 78%, 62% and 82% and numbers of species in each mattress system were 7, 11, 3. The evenness index of each mattress system was 0.86, 0.91 and 0.79 and diversity index of each mattress system was 1.67, 2.18 and 0.87. Removal rates of phosphorus at Phragmites australis, Zizania latifolia and Typha angustifolia which planted in mattress were 68.7%, 62.7%, 55.3% and removal rates of nitrogen of them were 79.8%, 74.7%, 64.9%. The removal rate of nitrogen was greater than phosphorus at all system and both removal rates were greater at Phragmites australis than at Zizania latifolia and at Typha angustifolia the rate was the least. Removal rates of PO4-3, NH4-N, NO3-N at Phragmites australis were 57.4%, 52.8%, 47.8% and at Zizania latifolia were 82.6%, 77.2%, 67.5% and at Typha angustifolia were 80.6%, 73.7%, 64.3%. It seems that removal effect is great by the planted mattress system.