The water quality in the Naktong River Basin was studied in 1968. Overall, the water quality was good, especially in the tributaries. The amount of total ions decreased in June and July due to increased river discharge. Water quality was best in the lower part of the river, followed by the middle and upper parts. Kumho river had higher conductivity than the main river, while Chongam had lower. The main river was contaminated by Kumho river and had high C.O.D. levels in June.