This work refers to study and calculate the concentrations of pollutants that emitted to air of the Baghdad city through the production of electrical power by electrical generator and small generators. The electrical power plant in Baghdad (area of study) consumed a large amount fuel for producing the electricity because of large number of people that living in this city. Fixed box model was used to explain the distribution of concentrations of pollutants and the rates of emissions of pollutants from the city. The pollutants that included in this study were carbon monoxide (CO), sulfur dioxide (SO₂), nitrogen oxides (NO_X), hydrocarbons, and particulates. The results showed a high accuracy (low error) between the measured concentrations by portable measuring device and the calculated concentrations by the Fixed box model for all pollutants. The average error up to 8%, 9%, 6%, and 5% for carbon monoxide, sulpher dioxide, nitrogen oxides, and particulates, respectively. The results showed that when the average velocities increased the pollutants concentrations decreased. The major source of HC was the electrical power plant for Ministry of Electricity by about 80% from the total pollutants that used different types of fuel, followed by Generator of state of Government and Emergency generator, then Mini-emergency generator.