Abstract:A method was found for calculating S input via atmospheric dry deposition.It consists of a series of calculation equations for surface layer turbulence charact eristic parameters (u*、θ*、L) based on profile meteorological data, for Vd of SO2 and SO42- particle dry deposition by making use of the resistance model, for S concentration of the atmospheric SO2 and SO42- particles, and thereupon for the targeted result.Experiments based on such a method were carried out in the Experiment Station of Red Soil Ecology, Yingtan, Jiangxi, Chinese Academy of Sciences and data collected at the experiment substation of farmland microclimate from Nov.1998 to April 1999.Results indicated that Vd of SO2 and SO42- part icle was 0.383~0.633cm/s (monthly mean 0.473cm/s), and 0.196~0.219cm/s (mont hly mean 0.205cm/s) respectively; total S input via atmospheric dry deposition per month was 4.35~16.32kg/m2 (av.8.73kg/m2.), of which 91%~98% (av.94.5%) was of SO2 dry deposition.Total S input via atmospheric dry and wet deposition per month was 7.03~17.53kg/m2 (av.10.51kg/m2), of which 61.9%~93.0% (av.80.2%) was of S input via atmospheric dry deposition.