Trees improve air quality through the accumulation of air pollutants in their leaves; however, the responses of different tree species to air pollution varies. Hence, this study evaluated the responses to air pollution of selected tree species in the Swamp Forest Research Station, Onne. Ten tree species (Cola pachycarpa, Khaya grandifoliolia, Irvingia gabonensis, Garcinia kola, Chrysophyllum albidum, Treculia africana, Dacryodes edulis, Tectonia grandis, Gmelina aborea, and Nauclea diderrichii) were selected based on their abundance in the area. Leaves were collected from all sides in 3 replicates for each tree species. Laboratory analysis was carried out using standard procedures. Portable Multi Gas Detector was used to determine the concentrations of air pollutants. One-way analysis of variance was employed to test for significant difference (p≤0.05) in biochemical parameters among the tree species while Pearson's correlation was utilized to determine the level of association between different biochemical parameters and APTI; heavy metals and APTI. Results showed high concentration of PM10, CO, moderate concentration of NO2, PM2.5, and VOC, and low concentration of ground O3. Heavy metals - Cadmium, Mercury, Lead, Nickel and Copper were all present in the tree species at varying rates. There were significant differences in the biochemical parameters and APTI values. C. pachycarpa exhibited the highest APTI value (89.88), while D. edulis had the lowest APTI value (8.24). C. pachycarpa, K. grandifoliolia, C. albidum, G. kola, T. africana, and N. diderrichii were identified as tolerant tree species to air pollution. G. aborea, T. grandis, and I. gabonensis were considered intermediate tolerant species, while D. edulis was the only tree species sensitive to air pollution. Ascorbic Acid, Chlorophyll, Hg and Ni had positive correlations with APTI; Cd and Cu had negative association with APTI at the 0.05 significance level. C. pachycarpa, T. africana, K. grandifoliolia, C. albidum, N. diderrichii and G. kola, are recommended for planting in pollution-prone areas.