Grazing is a key human disturbance affecting the structure and function of desert steppe ecosystem. Most of the current studies focus on the response of species or functional groups at a single level， and there is a lack of systematic analysis of the changing patterns of the correlation between the two with the change of disturbance gradient. In this study， Stipa breviflora desert steppe in Inner Mongolia was taken as the object， and four stocking rate gradients were set up. By measuring the characteristics of plant populations and dividing functional groups， the relationship between dominant species （Stipa breviflora， Cleistogenes songorica， Artemisia frigida） and functional groups （life form， photosynthetic type， root type） was analyzed by grey correlation degree. The results showed that： （1） The dominant species had different responses to grazing. Stipa breviflora and Cleistogenes songorica had strong grazing tolerance， and Artemisia frigida decreased significantly with the increase of stocking rate. （2） Perennial grass （PG） was always dominant in the community， C₄ functional group performed the best under moderate grazing， and the axis root system （ARS） was sensitive to grazing. （3） Grazing intensity regulated the association pattern of dominant species and functional groups： the two were the most closely related under light grazing （LG）， the dominant species contributed the most under moderate grazing （MG）， and heavy grazing （HG） led to the weakening of functional group association and community simplification. This study revealed the dynamic response of dominant species and functional groups to grazing， and provided a scientific basis for grassland management in arid areas.

Desert grassland  /  Dominant populations  /  Function groups  /  Correlation degree