Abstract: In order to explore the effects of saline water irrigation on afforestation in saline-alkali areas, so that utilizing the water resources effectively and enhancing the level of afforestation and virescence. The experiment used two kinds of irrigation techniques (saline water irrigation and saline and fresh water alternate irrigation), and carried out the experiment of irrigating the 9 gardens tree species with saline water of different salinity (0, 2, 5, 8, 12, 15 g/L), and studied the phenotypic characteristics of each tree species under different irrigation conditions. The results showed that: without affecting the growth of tree species, Fraxinus velutina Torr., Robinia pseudoacacia and Amorpha fruticosa for afforestation and virescence could be irrigated alternately by saline and fresh water with a mineralization degree of 12 g/L, Salix psammophila and S. matsudana with a mineralization degree of 8 g/L, Fraxinus chinensis, Fraxinus sogdiana Bunge, Pyrus betulaefolia Bunge and Elaeagnus angustifolia L. with a mineralization degree of 5 g/L. According to the survival of each tree species situation, the following could be determined: Salix psammophila, S. matsudana and Fraxinus chinensis were not suitable for direct irrigation with saline water, the other 6 tree species could be irrigated by saline water, and the salt-tolerance ability was: Elaeagnus angustifolia L (15 g/L)＞Pyrus betulaefolia Bunge (12 g/L)＞Fraxinus velutina Torr. (8g/L)＞Amorpha fruticosa, Fraxinus sogdiana Bunge, Robinia pseudoacacia (5 g/L).