Abstract: 【Objective】 In order to comprehensively understand and master the characteristics of water quality in Yili River reach, and to provide scientific basis for the prevention and control of water environment pollution. 【Method】 Four methods, single factor evaluation method, Nemerow index evaluation method, water quality index and principal component analysis were used to evaluate the quality of water environment in the north-south section of an inland urban river located in Yining. 【Result】 The results of single factor evaluation method and Nemerow index evaluation method showed that the comprehensive water quality of the water body in this section was in good condition. The main pollution factors were total nitrogen, total phosphorus, and chemical oxygen demand, expressed as organic pollution. The method of water quality index showed that there was no heavy metal pollution in the river being researched. The principal component analysis showed that the water quality of A5 section was the worst in this basin. The overall water area was characterized by higher overall pollution in the north of the river section than that in the south section and the water quality of upstream section was better than that of the downstream section. 【Conclusion】 The causes of summer water pollution in Yining reach of Yili River are related to domestic sewage, agricultural activities and industrial sewage.