Abstract:The Secondgeneration Sourcestrength Inversed Model 2 (SSIM2) is introduced, which depends on the meteorological background field supplied by MM5, and estimates the initial distribution of air pollutant sources by using the Avalue method of atmospheric environmental capacity, then calculates the concentration of air pollutants, and corrects the estimated distribution of air pollutant sources repeatedly until the distribution satisfies that the deviation between simulated and target concentrations is less than 5 percent on each grid point of the model domain. The verification by the air pollutant emission inventory of Changzhi in Shanxi province shows that the inversed distribution of air pollutants is much closer to the real one. The application of SSIM2 to the atmospheric environmental impact assessment for the urban planning of Tianjing and Suzhou shows that SSIM2 can provide a scientific basis for the allocation plan of air pollutant sources and the construction planning of new urban development zones.