Sabina vulgaris is the dominant sand-binding shrub species in the Mu Us Sandy Land. The widely distributed biological soil crusts （BSCs） in Sabina vulgaris community are of great significance to maintain the stability of desert ecosystem. Bacteria are an important part and play important roles in maintaining the structure and function of BSCs. However， the changes of diversity and composition of the bacterial communities with the development of BSCs are not fully understood. In this study， Illumina sequencing was used to analyze bacterial communities’ diversity and composition of four different developmental stages of BSCs （microbial， algae， lichen and moss crusts） and bare sand in Sabina vulgaris community in the Mu Us Sandy Land， and to explore the main environmental factors influencing bacterial community structure. Results showed that in the Mu Us Sandy Land， the diversity of bacterial communities significantly increased with the development of BSCs （P