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Two small agricultural watersheds were monitored from March 1998 to December 1999 to measure runoff and selected NPS pollutant loads. Runoff and water quality were measured every two weeks for SS, T-N,T-P and COD. Annual runoff coefficients ranged from 46.9% to 74.6% depending on rainfall amount and intensity. SS concentrations maintained most of the time the 1 st grade water quality standard of 25 mg/l or less while T-N concentrations could not meet the lowest reservoir water quality (5 th grade) standard of 1.5 mg/l all the time. It was analyzed that the constituents of T-N were mainly supplied from groundwater. T-P and COD concentrations were in between the first and the lowest water quality criteria. The importance of T-N control by means of nutrient management and rural wastewater treatment was emphasized. About 80 to 95% of the NPS pollutants were discharged during a short flooding period of 2 to 3 months. NPS pollutant load per unit area varied depending on daily rainfall. Patterns of pollutant discharges from the watersheds were different between monsoon and normal seasons. It was recommended that the use of pollutant load per unit area must be applied very carefully, and NPS pollutant control strategies for monsoon and normal seasons must be developed separately.