This study was to look out a better water quality of Tumen river by observing the variation of quality and causes of pollution for 30years since 1977 the negotiations between China and North Korea to present. China decreased industrial wastewater discharge and COD load by 71% and 94%, respectively through constant efforts since negotiation to present. But Tumen river is a boundary river so that the water quality should not be solved only by China. As the economics of North Korea recovers, industrial wastewater will be a big problem for a potential risk factor and it must to resolve by the negotiation between two countries. The main pollution sources in China are Chenming paper industry company, Shixian paper industry company and the urban sewage by population growth of Yanbian. Beneficiation wastewater of Musan iron mine has become a big SS pollution problem, and industrial wastewater including the strong organic matter and volatile phenol from Aoji chemistry company would have been a problem in North Korea. According to the ‘12.5’planning to improve water quality in Tumen river, the government planned bad V class(worse than 40mg/L COD) which occupies 9.7% of the water quality area presently to less than V class, and I~III class which occupies 71% to more than 80%. Construction of sewage treatment plants should be urgently needed in Yanji, Hunchun and 5 other cities.