Abstract: Three concentrations of artificial wastewater were discharged into the simulated wetland systems of Kandelia candel for one year. The photosynthetic rates of K.candel , leaf temperature, light quantum flux density and CO₂ concentration in a greenhouse were determined by a portable photosynthesis system at four different times after the test began. Results showed that there were high correlation between the photosynthetic rates of K.candel and the ecological factors in the greenhouse. Compared with the K.candel seedlings of control, the photosynthetic rates of strong wastewater treated groups dropped to some degree at the beginning, and restored to the same level by the end of sewage treatment. The study demonstrated that K.candel might have a strong resistance to artificial wastewater.