This study selected desert grasslands in Inner Mongolia, and designed three treatments: no grazing (NG), moderate grazing (MG), and heavy grazing (HG). The stoichiometric characteristics and synergetic relationship of nutrient elements C, N and P of dominant plant S. krylovii and soil were analyzed after five years, to reveal the mechanism of nutrient cycling in grazing ecosystem and provide theoretical basis for the utilization and restoration of regional grassland. The results showed that: (1) the species diversity of desert grassland was significantly higher than that of moderate and heavy grazing (P < 0.05). (2) The contents of C, N, C∶N, N∶P, C∶P in the soil all showed a trend of increasing firstly and then decreasing with the increase of grazing intensity, while the content of P in the soil increased with the increase of grazing intensity. (3) With the increase of grazing intensity, the contents of C in the aboveground part of S. krylovii decreased, and N, P, N∶P increased firstly and then decreased, while C∶P decreased firstly and then increased. The contents of C, N, N∶P in the underground part of S. krylovii have been increasing. P content firstly decreased and then increased, while C∶N, C∶P were contrary to the rule of P content. (4) Compared with the contents of elements in the aboveground part, the correlation between the content and ratio in the underground part of S. krylovii and the contents of elements in the soil is higher, which indicates that the root system of dominant plants in the desert grassland and its soil environment have certain cooperative change ability under grazing conditions.