| Stipa grandis steppe is a typical type of grassland in arid and semiarid area, which is a major grazing land in Inner Mongolia. Through field investigation and lab analysis, plant community characteristics, soil water content, hydrological effects of litter, ecological effects of snow, and their interrelationship at different grazing intensities were discussed. The results showed that: biomass, vegetation coverage, litter amount, litter coverage and soil water content, soil infiltration characteristics, and available soil nutrients declined and the soil bulk density and compaction increased with the grazing intensity increased, there is no significant change on plant species at different grazing intensities(P>0.05) and a negative correlation between vegetation coverage, biomass, litter coverage, litter amount and soil wind erosion. Soil wind erosion is a negative feed back to vegetation and soil characteristics which caused the changes of soil nutrients and physical parameters due to the key factors, grazing intensity. The relationship between biomass, soil water content and litter amount, water holding capacity of litter, and precipitation remaining of litter is positive. There is a positive relationship between litter coverage, height and snow depth and amount, and a negative relationship between litter coverage, height and snow wind erosion. Snow depth and amount have the positive correlation with the soil water content in early spring when grasses start regeneration, which have positive impacts on biomass and vegetation coverage. Water content, maximum water holding capacity and precipitation remaining of litter declined as grazing intensity increased. Plant functional groups, vegetation characteristics, soil features and their interrelationship were determined by grazing intensity. Therefore, grazing intensity is the key driven factor for the changes of vegetation, soil and plant functional groups in Stipa grandis grassland grazing system.
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