Based on the work of Williams et al in 1992, an inventory of soil NO_X emissions for China was developed.With the aid of a mesoscale meteorological model MM5 and a photochemical model Calgrid, effects of these emissions on tropospheric photochemistry in China were investigated.For the year 2000, it was estimated that the annual soil emissions in China amounted to 22518 Gg N, i.e.7% of the anthropogenic emissions.In summer, this fraction increased up to 23.4%, showing the importance of soil emissions to photochemical reactions.These emissions caused rise in average concentration of NO_X, O₃, HNO₃ and PAN (peroxyacetyl nitrate) and variation of spatial distribution of the pollutants as well.Their maximum increments on average reached 2.37, 26.08, 9.79 and 0.43 Lg m^-3, respectively, and the rising trend was much higher in summer than in any other seasons.The rise variedwith the sources of emission, meteorological conditions and photochemical characteristics.With increasing anthropogenic emissions, the role of NO_X emission from the soil will be more significant in tropospheric photochemistry and can not be neglected.