Non-point source pollution comes from many diffuse sources, unlike point source from industrial and sewage treatment plants. We have made lots of effort into the water improvement such as stream restoration and installing of riparian buffer zone beside non-point source pollution treatment. In this circumstance, a new direct purification system of stream corridor is demanded. Therefore, we accommodate a improvement of purification efficiency through the assessment of efficiency of the multiple wetland pilot plant using plants, vegetations and a new media that is one of the water quality management methods. As a result of the analysis of the removal efficiency of SS, BOD, COD, TN and TP in the multiple wetland pilot plant in this study, mean removal efficiency showed 90% for SS, 78% for BOD, 67% for COD, 83% for TN and 73% for TP. Consequently, the pollutant removal efficiency of in-situ application to the multiple wetland pilot plant would increases in both non-point sources and polluted steam treatment.