Extensive effort through point source controls, such as the construction of wastewater treatment plants, has been continuously made not only to improve the water quality but also to protect the water resources since 1990 in the Han River basin, Korea. However, it is difficult to maintain biochemical oxygen demand (BOD) concentration below 1.0 mg/L and not able to meet the standard for drinking water sources. One of the main reasons for not achieving the target of water quality management is pointed out as to take insufficient measures toward diffuse pollution, particularly in the control of stormwater discharge. In March 2004, the Comprehensive Measures for Non-point Source Pollution Management in the Four Major Rivers were established under the leadership of the Prime Minister's office and through the cooperation of related ministries. The effective control of Non-point Source (NPS) holds the key to the success of fulfilling total maximum daily loading (TMDL) program. As a part of carrying out policies on NPS pollution management, various types of NPS pollution pilot facilities were installed in the Han River basin at the end of 2005 and are continuously being installed in the other major rivers. The research program will be used to identify and design the Best Management Practices for the Han River and other river basins in Korea.