In Korea, there are four major rivers which are the most important water resources for 45 million peoples. To preserve the water quality, several water management policies had been adapted but they had been not successful because of focusing only on point source pollutants. With the establishment of the special act for four major rivers in 2002, which defined four watersheds, the watershed management was regularized. A Total Maximum Daily Loads (TMDLs) management system was introduced to control point and non-point source pollutants, and has been implemented for three major river watersheds from 2002 except the Han-river watershed, which is adopting the system voluntarily. This paper provides an overview of TMDLs management system and the implementation process and its progress in Korea. Also the next step for improving the management system is discussed.