Abstract: In order to reveal the characteristics of atmospheric nitrogen and phosphorus wet deposition in Erhai Lake area, we analyzed the total nitrogen (TN) and total phosphorus (TP) in rainwater of 4 stations located in the lake area from June 2019 to May 2020. Combined with the analysis of precipitation data and lake water quality monitoring data in the same period, we explained the temporal and spatial distribution characteristics of wet deposition pollutant concentration and deposition flux in Erhai Lake, estimated the wet deposition load into the lake, and evaluated the influence of pollution load into the lake on the water quality of the lake area. The results showed that: ① The annual precipitation in Erhai Lake Basin decreased from south to north and from west to east. The rainfall was mainly concentrated in June to October, accounting for 79%~96% of the annual rainfall. ② The average concentration of total nitrogen in precipitation was (1.18±0.682) mg/L, and the average total phosphorus concentration was (0.072±0.021) mg/L. The concentrations of total nitrogen and total phosphorus in rainwater showed obvious seasonal differences, and concentration was significantly negatively correlated with rainfall. ③ The deposition flux of total nitrogen and total phosphorus was the largest in July and the smallest in May, and the deposition flux was significantly positively correlated with rainfall. ④ The total nitrogen input to Erhai Lake by wet deposition was about 183.32 t, which accounted for 20.01% of nitrogen load by river inputs, and the corresponding total phosphorus was about 11.19 t, which accounted for 15.22% of phosphorus load by river inputs.