Soil microbial diversity is an indicator of species and genes of microbes in the soil ecosystem and their competitive interactions with the environment. The current study in this field is focused mainly on species diversity,genetic diversity,structural diversity and functional diversity. Although the study on soil microbial diversity as a global topic has been carried on forten remaining years,it has displayed features like huge variety of objects,magnitude of contents, broadness in level and novelty in method. However,molecular biological technologies lead and reflect progresses of the research and development of soil microbial ecology. Nowadays,how to improve soil microorganism culturing methods,how to intensify analysis and application of soil metagenomics,how to link soil microbial diversity with service function,and how to expose effect of microhabitat structure on soil microbial diversity,are the four key scientific issues. The basic value of the ecological service functions of soil microbial diversity,of course,lies in decomposing organic matter,recycling nutrients and regulating ecological safety. The study of soil microbial diversity in the years to come should center on its relationship with biological processes and ecological service functions,and establishment of an index system and a methodological system for the study on soil microbial diversity,and elucidation of biological processes of the effect of human activities on soil microbial diversity and its ecological service functions.