The purpose of this study is to estimate the adverse effects on ecosystems by the acid deposition of nitrogen oxides (NOx) in the Asian region. The source-receptor relationships of the model of long-range transportation, ATMOS-N, were used to calculate the wet/dry deposition of the nitrogen (N) in Asia with the emission inventory, REAS. Critical loads of N deposition in Asia were calculated from the relationships between the critical load of sulfur (S) and balance of N in and out using the data of critical load of S of RAINS-ASIA, the digital vegetation data of Global Land Cover Characteristics Database of USGS and the digital soil data of FAO Digital Soil Map of the World. In order to assess the environmental impact, the gaps between N deposition and critical load of N were calculated.
