Leaf functional traits can reflect adaptation and response of individual plants to environmental variability. In this study, we conducted a 20-day artificial fumigation experiment on nine common landscape plant species to examine the response of leaf morphological traits (individual leaf mass, individual leaf area, and specific leaf area), photosynthetic traits (photosynthetic rate and fluorescence parameters), and chemical traits (leaf nitrogen content, leaf phosphorus content, and N:P ratio) to different NO₂ concentration treatments. The experiments showed there were significant differences in the response of different plant leaf traits to NO₂ pollution, notably that different plants had different adaptation strategies to deal with NO₂ pollution. Leaf traits of the same plant under different concentrations of NO₂ varied in the same direction, but were of different magnitudes, which means the response strategy of the same plant to different NO₂ concentrations also varied. We found that most leaf trait relationships were consistent with the leaf economic spectrum. However, there was no significant correlation between leaf nitrogen content and specific leaf area (SLA). The lack of a significant leaf N-SLA relationship might be caused by the variations in environmental conditions. Our research revealed plant differences in response to NO₂ pollution, and these results are of great significance for predicting coevolution of plant functional traits and changes in plant ecological strategies brought about by urban air pollution.