Abstract: Based on the analysis of the monitoring data from 2015 to 2016, it was found that the inflow rivers in the west bank of Baima Lake was seriously polluted by nitrogen and phosphorus. In order to further understand the pollution characteristics of the inflow rivers of Baima Lake west bank and its impact on the water quality of Baima Lake, eight main inflow rivers were sampled in November, 2016. The concentration and formation of nitrogen and phosphorus were measured. The results showed that the pollution level of the eight inflow rivers was in the order of Hua River> Xun River> Wangliang River> Dadang River> Taoyuan River> Shanyang River> Caoze River> Fengchan River. The eight inflow rivers were seriously polluted by nitrogen. TN ranged from 1.41 to 9.12 mg/L, exceeding the standard level seriously. TDN which accounted for 65.61%-99.30% of TN was the main form of nitrogen in the inflow rivers. The pollution level of phosphorus was comparatively lower, the concentration of TP in Xunhe River exceeded Class Ⅲ of the Environmental Quality Standard for Surface Water by 0.2 fold, while the other seven rivers maintained at the Class Ⅱ-Ⅲ. The TDP accounted for 53.03%-96.70% of TP, which is the main form of phosphorus in the inflow rivers. The eight inflow rivers could be divided into three categories by the cluster analysis, with Hua River alone as one category, Wangliang River and Xun River as the second category, and Dadang River, Fengchan River, Taoyuan River, Shanyang River and Caoze River belonging to the third category. The results of factor analysis showed that the water quality of Huahe River, Wangliang River and Xunhe River was significantly affected by nitrogen pollution, the water quality of Wangliang River and the Xun River was mainly affected by phosphorus pollution, while that of Wangliang River, Dadang River and Shanyang River was affected by organic pollution. With the increase of the distance from the lake inflow, the concentration of TN, ammonia nitrogen, TP and permanganate index in Baima Lake west bank decreased, indicating that the inflow rivers had direct impact on the water quality of the lake, and the input of pollutants of inflow rivers should be the important reason for the decline of the water quality of Baima Lake.