The aquatic quality of the Naktong river after two of three months in June, 1991 with phenol spillage from a electrical factory in Kumi was investigated. The samples were collected at six sites of the Naktong river basin and Kachang and Kongsan lakes. Phenol was not detected from all water samples. Turbidity was very much increased to the down stream in the Naktong river. The BOD and COD values exceeded the 2nd grade(3 mg/l) of the Korean standard quality of Environmental Water Act at the all sampling sites of the Naktong river. Especially, the value of COD at Kaejin (12.5 mg/l) was poorly classified as to the 5th grade of water class for the environmental quality standards. Organophosphorous pesticides such as parathion, malathion, fenitrothion and diazinon were investigated but not detected. Diazinon was only detected at the Ilson bridge(1.42 ppb), Okkye stream(6.95 ppb), Waekwan bridge(0.32 ppb), Gangjung reservior(0.13 ppb), Kaejin(0.05 ppb). Of the carbamates such as carbanyl, isoprocarb and cabofuran, the carbofuran was detected all sites except tap water, and Kachang and Kongsan lakes. The content of heavy metals such ans Cd, Pb, Zn, Fe, Mn, Hg were not exceeding for drinking water standards at the all sampling region, but only mecury was detected from Okkye stream(0.018ppb) and Kaejin(0.09ppb). In the regions of Kachang and Kongsan lakes, the content of heavy metals were lower than that of reservoir of Naktong river.