Clean air, pure water and food are basic amenities of life but the quality of air, water and land is deteriorating continuously. That is due to the major problem the earth is facing today which are global warming and air pollution. Air pollution resulting from vehicular emissions is more complex than most other environmental challenges. No physical or chemical method is known to ameliorate air pollution resulting from vehicular emissions. A suitable way is to grow green plants and trees along roadsides, Since air pollution tolerance level differs from species to species, thus the determination of Air Pollution Tolerance Index (APTI) and Anticipated Performance Index (API) of the plant species in urban area is important to identify for implementing pollution control methods. Plants with high APTI and API values are more tolerant to air pollution. The identification of the tolerant plant species suggests appropriate species for growing especially in polluted areas. Hence in the present study Air Pollution Tolerance Index (APTI) for 10 avenue tree species has been evaluated by analyzing four important chemical parameters which are total chlorophyll content (TCH), Ascorbic acid (AA), Leaf extract pH and Relative water content (RWC). The studied species are the most common trees which are grown in Sultan Qaboos Street in Muscat, Oman. The Anticipated Performance Index (API) of these plant species was also calculated by considering their APTI values together with other socio-economic and biological parameters. Based on these two indices, among the studied plant species the most suitable one for clean avenue environment was Ficus benghalensis and it be recommended for extensive planting. Conocarpus erectuse, Phoenix dactylifera and Pithcellobium dulce were also judged to be as good performers but their API value were less than Ficus benghalensis. However, Azadirachta indica qualified in the moderate category. Besides these species, the remaining four species were found to be unsuitable as pollution sink because of their lower anticipated performance. Also, the study evaluated the correlation coefficient between four parameters of plants in APTI formula. A close correlation between APTI and AA was evident. A significant correlation was found between APTI and TCH, APTI and pH. In addition, a significant correlation was also found between AA and TCH, RWC and TCH.