Currently, Gausses model is used commonly to calculate and predict pollution in assessment of air environment. Gausses model, when calculating is based on some assumptions, in which the pollutants are not deposited during their dispersion. Actually, gravity of particulate matter is so larger than gases. Hence, they are setting down while transferring into atmosphere. This paper gives out air pollution dispersion method, which mentions to depositing of particulate matters during transfer. Simultaneously, calculation and comparison the difference of particulate matter ambient concentrations between two options: mention or not mention to deposition of the dusts.