This study combines air pollution tolerance index (APTI) and anticipated performance index (API) in order to determine the potential of trees and ornamental shrubs that are frequently growing on the roads of Quetta, Pakistan, and the campus of the University of Balochistan, in Quetta, for green belt development. Our investigation exposed that not only APTI is suitable for the fitness of trees for building green belts. It is used to categorize vulnerable plant species for only bio-monitoring. The grouping of APTI and API in the present study is a practical technique for decreasing air pollution control. Laboratory analysis for APTI was carry out by the four physico-biological factors such as leaf extract pH, total chlorophyll content, ascorbic acid content, and relative water content. API for different plant species (trees and ornamental shrubs) was determined depending upon the characteristic grading by allotted + or – to the plants. The standard for determining API is given in Table 2. For examining the relationships among these factors statistics were utilized. This study indicated that the APTI is used as an instrument for choosing suitable plants to reduce environmental urban heat. API designated that Morus alba L., Pinus halepensis Miller, Ficus carica L., and Pistacia vera L. with API = 6 are excellent performers for green belt development. Morus nigra L. and Malus pumila Miller had API 5 and are considered very good performers, and Fraxinus angustifolia Vahl., Prunus armeniaca L., and Platycladus orientalis L. showed 4 API values with good performance for green belt formation. All the other remaining investigated trees and ornamental shrubs demonstrated poor values of API and are not recommended for green belts as they act as bio-indicators. Data also exhibited that all the examined trees had higher API values then the ornamental shrubs. This study suggested that the integration of both APTI and API of plants is extremely beneficial for the construction of green belts.