Soil microorganism,as an important decomposer,plays critical roles in the nutrient cycling and energy flow in forest ecosystem,which is often dependence of temperature.We established a field warming experiment to explore the effects of warming on soil microbial communities of the monsoon evergreen broad-leaved forest in Dinghushan National Nature Reserve in south subtropical region of China.Soil samples were collected in layers of 0-10 cm and 10-20 cm to monitor structure of soil microbial community by using the phospholipid fatty acids (PLFA) as biomarkers.The results showed that:(1) The warming treatment did not significantly alter soil moisture in both soil layers,while averagely increased soil temperature by 1.24 ℃ in 0-10 cm and 1.17 ℃ in 10-20 cm soil layers,respectively.(2) The warming treatment significantly increased soil nitrate content,but no significant effect was found on other soil physical and chemical properties.(3) The warming treatment has no significant effect on soil microbial biomass carbon (MBC),microbial biomass nitrogen (MBN),the ratio of MBC to MBN or microbial total PLFAs content.(4) The warming treatment significantly changed soil microbial community structure,with increases in the relative abundance of bacteria,the ratio of bacteria to fungi and the ratio of Gram-positive bacteria to Gram-negative bacteria but decreases in the relative abundance of fungi and arbuscular mycorrhizal fungi.And (5) further analysis showed that soil nitrate nitrogen and soil organic carbon was the most important influencing factors,explaining 60.5% variability of microbial community structure under the warming treatment.These findings indicate that climate warming may alter soil microbial community structure instead of soil microbial biomass by influencing soil nitrate nitrogen and soil organic carbon in the southern subtropical monsoon evergreen broad-leaved forest,in turn resulting in an effect on soil carbon and nitrogen processes by microbial assimilation.