Abstract:In order to understand the effects of exogenous proline and phosphate fertilizer under salt stress, the growth and physiology index of Populus cathayana seedlings were studied with different treatment. The results showed that the growth and biochemical substances contents in female and male seedlings were affected under salt stress, while the application of proline and phosphate fertilizer could improve the salt tolerance of male seedlings to a certain extent, but it was not obvious on female seedlings. Therefore, it is better to choose male seedlings with strong stress resistance in the improvement of saline alkali land, and at the same time, it is considered to choose phosphate fertilizer for enhance salt tolerance of plants because of affordable and easy to use.