Abstract: In order to study the influence of haze on the photosynthetic characteristics of evergreen in winter in North China, the net photosynthetic rate (Pn), transpiration rate, stonmatal conductance of leaves were analyzed by CL-340 and difference between species was compared with 4 representative evergreen（Euonymus japonicus, Agave sisialana, Ligustrum lucidum, Buxus sinica var.parvifolia）in Tianjin. The results showed that the photosynthetic characteristic of all plants decreased significantly,and the net photosynthetic rate, transpiration rate, stonmatal conductance of 4 species were negatively correlated with PM2.5. The correlation coefficient of the PM2.5 content in the atmosphere and the net photosynthetic rate of the 4 species, Euonymus japonicus, Ligustrum lucidum, Agave sisialana, Buxus sinica var.parvifolia were respectively -0.87、-0.78、-0.88、-0.84,which showed a strong correlation; the correlation coefficient with transpiration rate of leaves were -0.82、-0.80、-0.72、-0.67 successively, meaning stronger correlation in Euonymus japonicus and Ligustrum lucidum, which were above 0.80; the correlation coefficient with stonmatal conductance were -0.737、-0.895、-0.794、-0.783 successively,which had a strong correlation with Agave sisialana. Meanwhile,the net photosynthetic rate of 4 species were siginificantly different under influence of haze. It shows：Agave sisialana has strong resistance to haze.

Key words: winter, evergreen plant, photosynthetic characteristic, PM2.5, correlation