Abstract: Based on the theory of ecological stoichiometry, this paper chose Leymus chinensis collected from saline-alkaline grassland in western Jilin Province as the study object and studied the influence of different degrees of saline-alkaline grassland on nitrogen and phosphorus contents and their ratio in different organs of Leymus chinensis. The results showed that with the increase of soil pH value, nitrogen and phosphorus contents decreased wholly. The contents suddenly increased to the peak in the medium saline-alkali grassland (pH 9.16-9.35), and then the nitrogen content declined while the phosphorus content increased. The N/P values of root, stem and leaf all declined to the minimum value in medium and severe saline-alkali grassland. The nitrogen and phosphorus contents of the aboveground part were higher than that of the underground part. Nitrogen and phosphorus contents of Leymus chinensis declined with the increase of soil pH value, but the change was not obvious. Thus, the ability of Leymus chinensis’ resistance to saline-alkaline grassland was quite remarkable and it could be the dominant grass for the reconstruction of saline-alkaline grassland in western Jilin Province.