The present study reviewed the methodologies currently applied to atmospheric nitrogen deposition observation in China, as well as analyzed the long-term trend of the nitrogen deposition observed in the Pearl River Delta (PRD) region, South China. The atmospheric nitrogen deposition flux decreased from the southeast coast to the northwest inland, and the ecosystems influencing by more human activities tended to be of higher deposition load. The wet deposition fluxes were in the range of 18~38kgN/(hm²·a) and 6~78kgN/(hm²·a) for forest ecosystem and cropland ecosystem, respectively. More specifically in cropland, the fluxes of bulk deposition and dry deposition were respectively 15~133kgN/(hm²·a) and 54~83kgN/(hm²·a). And the bulk deposition flux in the urban ecosystem had achieved to 101kgN/(hm²·a). In the PRD region, the deposition fluxes of total nitrogen and the ratio of NH₄⁺-N/NO₃^--N were declining in the past years. This could be explained by the industrial structure adjustment and the huge energy consumption accompanied with urban development. In general, the measurements for nitrogen deposition observation in China are becoming more and more diversified, and the results are also becoming more convincing. However, the observation is very scarce in the remote areas and wet deposition and bulk deposition, while the study of dry deposition is still insufficient.