Abstract: Two neutral salts (NaCl∶Na₂SO₄=9∶1) and two alkaline salts (NaHCO₃∶Na₂CO₃=9∶1) were used to simulate different salt and alkali stresses on organ growth and ion metabolism and their adaptation strategies in 35 d old potted seedlings of Leymus chinensis. The dry weight of all organs, clonal growth (rhizome daughter and tiller daughter shoots), photosynthesis and K⁺ contents decreased significantly while Na⁺ content and Na⁺/K⁺ ratio increased significantly, with increased salinity and alkalinity. Under a high concentration of 200 mmol/L, the change of all variables was higher under alkali than under salt stress. Under the two stresses, the biomass reduction of rhizomes was the largest and that of daughter shoots from rhizomes were higher than those from tillers. Under salt and lower alkali stresses, the changes of Na⁺, K⁺ contents and Na⁺/K⁺ ratio in rhizomes and roots were greater than those in stems and leaves. Under higher alkali stress, the Na⁺ content increased significantly in stems and leaves. In conclusion, L. chinensis was resistant to salt but not to alkali at the same concentration, especially at the higher concentration. Under salt and lower alkali stresses, L. chinensis had similar strategies of growth adaptation and Na⁺, K⁺ metabolism. Rhizome growth and daughter shoots were reduced to maintain development in situ and to compartmentalize the Na⁺ into rhizome and root to avoid stem and leaf growth damage. However, the high pH stress exceeded the carrying capacity of rhizome and root, leading to much Na⁺ transportation to stem and leaves, where it influenced photosynthesis and restrained growth. Either in growth adaptation or in Na⁺, K⁺ metabolism, the existence of rhizomes played a protective role to mitigate the harmful effects of salt or alkali stress on the other organs.