The desert steppe is one of the most concentrated distribution in the Inner Mongolia region and representative types of temperate grassland in China for studying systems ecology.The desert steppe is located at the grassland-desert ecotone,and is an ecosystem that is very sensitive to global changes.However,Grassland degradation has seriously affected the function and productivity of this ecosystem under the dual pressures of continuous drought and long-term overgrazing.Grassland degradation not only affects local agricultural production and everyday human life,but also threatens the ecological environment of central cities in china.This has become an urgent regional environmental issue,especially for the sustainable development of animal husbandry.Today most research on the desert grassland ecosystem examines vegetation characteristics,physical and chemical soil properties,animal behavior,and so on.However,less research exists on the underground soil microbial community structure.The Inner Mongolia desert grassland is an important part of the grassland in north China,with a unique plant species composition and range of community types,structures,and functions.Soil microbial communities are also important components of grassland ecosystems.They are dominant contributors to biogeochemical cycles,participating in the decomposition of organic material in soil,and are critical for maintaining the stability and biodiversity of grassland ecosystems.Research on the soil microbial community structure and diversity of Stipa breviflora(needlegrass)on the desert steppe in Inner Mongolia will have important ecological significance to the rational utilization of grassland,will contribute to understanding the biological functions involved in restoring degraded grassland ecosystem,and will help realize the sustainable development of grassland ecosystems.In order to understand the characteristics of the soil microbial community structure of the S.breviflora desert steppe in Inner Mongolia,we adopt high-throughput sequencing technology to relatively comprehensive research the soil microbial community structure of S.breviflora on the desert steppe in Inner Mongolia.We extracted DNA of the soil microbial community of the desert steppe in Inner Mongolia.Soil bacterial community structures of the v4-v5 16S rDNA gene region and fungi community structures of ITS1-ITS2 were examined by high-throughput sequencing technologies.The results showed that 13711 and 5929 OTUs were obtained from soil bacterium and fungi.Based on the results of species classification,bacterial communities belonging to 29 phyla,57 classes,111 orders,191 families,and 485 genera.Among them,the dominant populations were Gammaproteobacteria and Thermoleophilia,and their relative abundances were 32.68% and 26.83%.Fungal species belonged to 4 phyla,16 classes,45 orders,78 families,and 105 genera.The dominant species were Ascomycota and Basidiomycota,and their relative abundances were 35.76% and 25.90%.Bacterial communities were more diverse and had greater species richness than fungal community in the soil.