Abstract: To know nitrogen species and nitrate isotopic composition in wet deposition in Jiaozuo;city, identify quantitatively the sources of nitrate and its formation processes, forty-one wet deposition samples were collected from January 2020 to December 2021 in Jiaozuo City. The concentrations of total nitrogen (TN), ammonia nitrogen (NH₄⁺-N), nitrate nitrogen (NO₃⁻-N),  δ¹⁵N-NO₃⁻ and δ¹⁸O-NO₃⁻ were measured.  The results showed that TN, NH₄⁺-N and NO₃⁻-N ranged from 2.52 to 13.27mg·L⁻¹, 0.11 to 1.70 mg·L⁻¹,1.64 to 8.31mg·L⁻¹, respectively. NO₃⁻-N accounted for from 52.11% to 83.92% of TN, indicating that nitrate nitrogen is the dominant species of nitrogen. δ¹⁸O-NO₃⁻ and δ¹⁵N-NO₃⁻ values ranged from 54.87 to 93.93‰, -9.76 to +2.97‰, respectively. δ¹⁸O-NO₃⁻ values in the non-raniny season samples (62.48 to 93.33‰) were close to calculated δ¹⁸O-HNO₃ values by N₂O₅ pathway(100.93~103.13‰), while δ¹⁸O-NO₃⁻ values in the rainy season samples (53.16~73.03‰) were close to calculated δ¹⁸O-HNO₃ values by OH pathway(50.92~60.89‰), indicating that nitrate in wet deposition is largely from N₂O₅ pathway in non-rainy season, while is largely from OH pathway in rainy season. Averaged fractional contributions of N₂O₅ pathway were 65.37% and 80.32% in non-rainy season and in rainy season, respectively, those of OH pathway were 46.51% and 19.67%, respectively. The contributions of the four potential nitrate sources were calculated by the Bayesian mixing model. The results showed that the contributions of soil emission, biomass combustion, vehicle emission and coal combustion were 31.70%±4.90%、28.30%±14.00%、22.80%±12.10%、17.20%±0.08%, respectively.