Abstract: Puccinellia tenuiflora seedlings were treated by alkaline salt solution that was made up according to ions composition of the alkaline soil of Songnen alkaline grassland. Contents of several osmotica in above-ground part of P. tenuiflora seedling under alkaline salt stress were determined. With the increment of alkaline salt concentration and stress days, content of Na⁺, soluble salt, free proline and soluble carbohydrate increased gradually, and the change of free proline is the greatest. Under the stress of alkaline salt which concentration is smaller than 20 g L^-1, K⁺ content decreased a little with the stress days, and under the concentration of 40 g L^-1 and 60 g L^-1, K⁺ content decreased first, and then increased rapidly.

Key words: Puccinellia tenuiflora, Alkaline salt stress, Osmotica