1. The authors checked the water pollution and its effect to the fish fauna at 11 stations along the creeks of the Jeonju-cheon, the Sam-cheon, and the Mangyong River respectively from June through October 1975 (Figs. 1 and 2 ; Tables 1 and 2) 2. Oxygen deficit was found to be as an important limiting factor regulating the fish ecological distribution, certainly due to the eutriphication of wastes and city sewage from the nearly districts. 3. As the pollution intensified during the period of the survey, the total numbers of fish species decreased gradually and the abundance of the dorminant species was found more distinct in the fish composition ratio as compared to the nonpolluted water areas. 4. All fish species in this studied area could be classified into 3 kind of groups as regards the tolerance for water pollution; intolerant, tolerant and intermediate species. 5. The current code controlling merely the quality of waste water should be considered for its revision, so that it might include the checking not only the kind of matters in waste waters but also the total volume of waste waters discharged from industrial pollution sources.