An important source of plant nutrient and soil acidification, increased N deposition from the atmosphere will greatly impact the production and stability of global terrestrial and aquatic ecosystems. This paper introduced the concepts, sources and methods of atmospheric nitrogen deposition and reviewed recent literatures on the forms and amounts of atmospheric nitrogen as well as its ecological effects on red soil agro-ecosystems. Finally, the existing problems and research trends of atmospheric nitrogen deposition were proposed in red soil agro-ecosystems.