Substances are put into air by the activity of mankind into concentration sufficient to cause the harmful effect to health, vegetables, property on interfere with the enjoyment of his property. Present investigation mainly deals with the constant mean model and it found that the air pollution is decreasing in Agra city due to the impact of Supreme Court intervention in 1996. All assumptions of constant mean model are lied and observations are generally uncorrelated. The application of constant mean model on the air pollution data of NO₂, SO₂ and SPM level of Agra city, U.P. (India).