Nitrogen (N) deposition elevation has induced severe impacts on the N transformations and N losses of forest ecosystems. For a better understanding the responses of nitrous oxide (N2O) emissions to the elevated N depositions, a two-year field investigation was conducted in a subtropical forest that received natural N deposition (Ct, 0 kg N ha-1 yr-1), low N addition (LN, 35 kg N ha-1 yr-1), medium N addition (MN, 70 kg N ha-1 yr-1) and high N addition treatments (HN, 105 kg N ha-1 yr-1). Gas samples were collected two times in each month and continued for two years. In addition, soils of the subtropical forest were collected in a wet season and in a dry season, for the determination of soil physiochemical properties and nitrifying and denitrifying functional gene abundances. This study was aimed to explore the underlying mechanisms of soil functional microbes in responding to elevated N depositions and