This study was performed to characterize stormwater runoff of pollution material fromnonpoint sources during rainfall in drainage basins of Hongjechun watershed, and to suggestmanagement methods to control the first flush of nonpoint sources. We conducted 4 times offield surveys including 3 times of wet period and 1 times of dry period for 5 stations, whichconsist of 3 stations in main stream of Hongjechun and 1 station in tributaries of Sinyoungchunand Gukichun, respectively. The variation of pollutant concentrations in terms of BOD, COD, SSand TP was large depending on the flow rate of stormwater, while a little change of TNconcentration was investigated. Depending on the rainfall event, the difference of flowrates, andrunoff loadings was large, while the difference of those for dry wether period was not noticeablefor various sub-basins. In the results of unit load calculation, the range of 153-277 kg/ha/yr forBOD, 222-422 kg/ha/yr for COD, 264-432 kg/ha/yr for SS, 40-70kg/ha/yr for TN, and 13-25kg/ha/yr for TP was obtained for Hongjechun, Sinyoungchun, and Gukichun sub-basins.Compared with the previous studies, the result of this study was founded to be acceptable.