[Objectives] To explore the response characteristics of chlorophyll and photosynthesis in Styrax tonkinensis under different concentrations of copper and cadmium stress and analyze the internal mechanism of the effects of copper and cadmium pollution stress on photosynthesis. [Methods] Taking seedlings of S. tonkinensis as the research object, the response characteristics of chlorophyll and photosynthesis of S. tonkinensis were compared under different concentrations of copper and cadmium. [Results] With the increase of copper and cadmium treatment concentrations, the chlorophyll content first rose and then fell. With the increase of cadmium concentration, the net photosynthetic rate of S. tonkinensis plants increased from decrease to increase, and the stomatal conductance, transpiration rate and intercellular CO2 concentration all increased. [Conclusions] Under the stress of different concentrations of cadmium, the photosynthetic characteristics of S. tonkinensis were not obviously inhibited. Copper stress has inhibitory effect on photosynthesis of S. tonkinensis.
