Toady, one of the main factors contributing to the air pollution in such metropolises as Tehran are the suspended particles resulting from automobiles, heavy traffic on the roads, and different industrial activities.PARTICULATE MATTER (PM) is a generic term used to describe a complex group of air pollutants that vary in size and composition, depending on the location and the time of their dispersion. The PM mixture of fine airborne solid particles and liquid droplets (aerosols) include components of nitrates, sulfates, elemental carbon, organic carbon compounds, acid aerosols, trace metals, and geological materials.ADMS-Urban is an advanced model which is used for calculating concentrations of pollutants emitted continuously from point, line, volume, and area sources and of pollutants emitted intermittently from point sources. The model is an advanced Gaussian-type model and uses Gaussian distribution for such concentrations and is recommended for regulatory use for multiple buoyant or passive industrial emissions from urban or rural areas of flat or complex terrains with transport distances less than 50 km and periods of time ranging from a few seconds to a year.The percentage of the suspended particles and meteorological parameters such as the speed and direction of the wind, temperature, and cloud cover were measured for the city’s municipality District 22 over a year, twice in a day (morning and afternoon), and for one week in each month. The data were collected at 13 mobile measurement stations during the critical time of traffic (the time with the highest rate of density and dispersion of suspended particles in the air).The obtained results were presented in the GIS environment of the District because of the availability of sheets in that environment. The output of this mathematical model was compared with the inventory model (databank) of the air pollution in District 22. The results showed a similarity between the output of the mathematical modeling and the real measured data.This model has been used for the first time for modeling the pattern of particles emission in Tehran. The results also showed that due to the existing vehicles and traffic, Tehran-Karaj freeway and the eastern border of District 22 had the highest density and concentration of suspended particles.