Abstract: In order to investigate the effects of salt stress on seedling growth of Xanthocera ssorbifolia Bunge, the survival rate, seedling height, ground diameter, biomass, root-shoot ratio and stem-leaf ratio of annual Xanthocera ssorbifolia Bunge seedlings were analyzed under different concentrations (0%, 0.2%, 0.5%, 0.8%) of salt (NaCl:Na2SO4=9:1) stress treatment. The results showed that seedling growth indicators presented a gradual downward trend with the increase of salt concentration, the growth was inhibited obviously, ground diameter, root dry weight, root-shoot ratio were higher than that of control under mild salt stress (0.2%); seedling growth indexes were significantly lower than that of control under moderate (0.5%) and severe (0.8%) salt stress. The seedling survival rate reached 100% under control, mild and moderate salt stress, the seedling survival rate decreased significantly under severe salt stress. Tests showed that under salt stress, seedling survival and inhibiting effect under control and mild salt stress were weaker than that of moderate and severe salt stress. The seedling could maintain normal growth by thickening the stem, increasing root growth under mild salt stress; 50% of the total biomass was defined as the threshold of salt-tolerance of seedlings, and the threshold of salt-tolerance of Xanthocera ssorbifolia Bunge seedlings was 0.8%.