Abstract: In order to understand the influence of nitrogen deposition on the aquatic ecosystem at Daya Bay, measurements of variations of concentration and deposition fluxes on precipitation were made. Results showed that, volume-weighted concentrations in wet deposition for ammonium nitrogen (NH4+-N), nitrate/nitrite nitrogen (NO3--N/NO2--N) and total nitrogen (TN) were 0.474, 0.536 and 1.23 mg/L, respectively, the nitrogen concentration peaked in August; their wet deposition fluxes were 58.93, 78.13 and 158.75kg/km2/month, respectively; inorganic nitrogen accounted for 86.34% of the total nitrogen. The nutrients in the atmosphere excited mainly in the form of NO3--N/NO2--N. Compared with the observations in 2009, the deposition flux of nitrogen increased about 1 times in 2012， The inputs of nitrogen from the atmosphere represented an important role in the process of eutrophication at Daya Bay. Therefore, the contribution of precipitation should be considered in the research of eutrophication.