To investigate the water quality characteristics and eutrophication of the Keum River, survey were conducted on samples collected from 6 stations in Aug. and Oct. in 1995 and Jan. and May in 1996. The results were summarized as follows ; Concentration of pollutants were in the range of 1.74∼6.35(mean 3.81)㎎/ℓ for BOD and 1.98∼8.21(5.14)㎎/ℓ for COD and 1.46∼51.94(18.52) g/ℓ for TSS. Water quality were evaluate to be 2∼3 grade of station 1 and other stations were 3∼4 grade of water quality criteria. The concentration of nutrients were in the range of 55.2∼735.3(309.3)㎍-at/ℓ for Dissolved inorganic nitrogen(DIN) and 0.06∼6.03(2.80)㎍-at/ℓ for dissolved inorganic phosphate(DIP). Nutrient concentrations in Keum River were usually high and the DIN/DIP ratio ranged from 72 to 2648. The concentration of chlorophyll-a was in the range of 1.1∼143.7(44.3)㎎/㎥. Chlorophyll-a concentration were high 10㎎/㎥ except station 1, which is the value of eutrophication criteria by EPA. Correlations between nutrients and chlorophlly-a were not significant. According to eutrophication evaluation, Keum river was equivalent to the eutrophic state.