AbstractSoil health is important for the sustainable development of terrestrial ecosystem. In this review, we summarizes the relationship between soil quality and soil microbial characteristics such as soil microbial community structure, soil microbial biomass and soil enzymatic activity in order to illustrate the function of soil microbial characteristics as bio-indicators of soil health. Many studies have showed that the soil nutrient is correlated with the quantity or the composition of bacteria, fungi and actinomycetes in soils. In general, higher ratio of soil bacteria indicates better soil quality and higher soil nutrient content. Soil microbial bio-mass is closely correlated with soil organic carbon, and the ratios of soil microbial biomass carbon to soil or-ganic carbon(C_mic : C_org) and microbial metabolic quotient (qCO2) reflect the use efficiency of soil organic C. The activity of soil enzymes are positively correlated with soil microbial biomass carbon and nitrogen. Therefore, soil microbial characteristics reflect the changes of soil quality and thus can be used as bio-indicators of soil health.