To understand pollutant purification effects of riparian buffer, field experiments with simulated farmland fertilization were conducted on riparian buffer strips of grass and planted forest, respectively. The surface runoff water and seeped water were collected and analyzed for total phosphorus(TP), total nitrogen (TN), ammonia nitrogen(NH₄-N)and suspended solid matter. The results show that the grass riparian buffer were significant better than the planted forest riparian buffer in terms of phosphorus removal in sur-face runoff water, while both of the buffer strips were similar in terms of nitrogen interception. Planted for-est showed similar efficiency for the interception of TN, TP and NH₄-N in both surface runoff and seeped underground water. The grass riparian buffer was superior to the artificial forest in terms of removing sus-pended solid matter. As expected, more pollutants were removed with wider riparian buffer. Human dis-turbances might be the main reason of weak pollutant removing ability of artificial forest riparian buffer. Finally, this study provided some practical suggestions for riparian buffer management.