A　one-year　study　in　a　typical　agricultural　region　of　Southeast　China　was　conducted　to　determine　atmospheric　nitrogen　fluxes　of　typical　N　compounds　and　contribution　of　two　sources　(wet　and　dry　deposition)　to　N　deposition.　The　results　show　that　ammonia　was　the　major　component　within　the　samples,　accounting　for　55-60%　of　the　dissolved　inorganic　nitrogen　concentrations.　For　one　year　in　2004,　the　total　atmospheric　N　deposition　was　28.8　kg　N　ha-1,　with　wet　deposition　accounting　for　93.8%　of　the　total　deposition.　Ammonia　was　the　predominate　contributor,　accounting　for　64.4%　of　the　total　deposition.　Therefore,　atmospheric　N　deposition　should　be　considered　when　water　eutrophication　and　critical　loads　of　atmospheric　deposition　on　agricultural　system　are　estimated.　©　2011　IEEE.