Soil microorganism plays a key role in organic matter conversion and nutrient cycling.It is very crucial to clarify the variations of microorganism in soil profiles to understand the mechanisms of microbial community regulating ecosystem functions.The diversity and formation mechanism of soil microbial communities have been mainly studied in the surface soil, but rarely in deep soil horizon.However, the role of microorganism in deep soil horizon in soil formation, carbon sequestration and elemental chemical cycling should not be ignored.Therefore, in this study, we reviewed the research progress of vertical spatial distribution of soil microorganisms in different ecosystems, and analyzed the succession of microbial abundance, diversity and community composition along the soil depth and their relationship with soil physicochemical properties.In addition, this study expounded the changes of assembly processes and interaction patterns of soil microbial communities with the soil depth, and looked forward to the future research priorities, in order to provide a theoretical basis for understanding the soil formation mechanism and protecting and utilizing soil resources.