Foliar surface undergoes several structural and functional changes when particulate-laden air strikes it. An attempt was made to evaluate the quality of air in terms of respirable suspended particulate matter (RSPM), suspended particulate matter (SPM), sulphur dioxide (SO2) and nitrogen dioxide (NO2) along with biochemical parameters of twelve selected roadside plant species at industrial, traffic, residential and rural areas of Rourkela city in India. Increase concentration of heavy metals (Fe, Cu and Zn) was recorded at site B (industrial area). Considerable reduction in chlorophyll, sugar and protein contents were observed at sites receiving higher pollution load. The variation in heavy metal concentration and enzyme activity (Catalase, Peroxidase) were found to be pollution load dependent, suggesting the activation of protective mechanism in these plants under air pollution stress. A significant negative correlation was found between ambient air quality and biochemical parameters except for ascorbic acid which exhibited significant positive correlation with pollution load.