We investigated net photosynthetic rate and antioxidative enzyme activities in Erythrina orientalis grown in three different sites: Makati and Quezon (cities with high levels of air pollution, HP) and La Mesa (a non-polluted area, NP). Photosynthetic activity of E. orientalis was significantly reduced in the HP cities. In contrast, activities of the antioxidative enzymes ascorbate peroxidase and glutathione reductase were significantly higher in HP cities than in the NP area. and S. Y. Woo, D. K. Lee, Y. K. Lee.