【Objective】Unreasonable anthropogenic activities tend to cause gradual increase in global atmospheric nitrogen deposition, which has become one of the most important environmental problems that arouses attentions the world over. Red soil, as an important soil resource in China, has come to face a series of serious ecological problems, such as soil acidification, biological degradation and so on, owing to its own development characteristics and specific climate factors. At the same time, nitrogen deposition is liable to exacerbate soil acidification and degenerate functions of the red soil ecosystem, posing a serious threat to the red soil ecosystem and impeding sustainable development of the economy and society of the red soil region. In order to promote restoration and sustainable development of the ecological functions of red soil, a series of practices have been adopted, such as leave farmlands in fallow or “grain for green” and stop artificial interference of the soil to let the vegetation and then the soil recover in biodiversity and ecosystem function through natural succession. This study was oriented to explore the effects of atmospheric N deposition on the soil microbial community in the rhizosphere ofSetaria viridis (L.) Beauv Beauv, the dominant plants in fallow farmlands in the initial phase of the succession, as affected by soil acidification, controlled by liming. The factors of global change and comprehensive impact of artificial management practices were also taken into account.【Method】For the study, a field experiment designed to have three levels of artificial atmospheric N deposition, through N application, i.e., 0 kg•hm^-2，45 kg•hm^-2 and 90 kg•hm^-2 and two levels of liming, i.e., 0 kg•hm^-2 and 110 kg•hm^-2. Samples of rhizospheric soil under Setaria viridis (L.) Beauv were collected and analyzed for the structure of the soil microbial community.【Result】Results showed that the simulated nitrogen deposition significantly inhibited the soil microbial community in rhizosphere by reducing its microbial phospholipid fatty acid (PLFA) content, the ratio of gram-negative bacteria/gram-positive ones, fungi / bacteria ratio, and Shannon diversity. In the plots without nitrogen deposition (0 kg•hm^-2), liming decreased microbial PLFA, but significantly increased the ratio of Gram-negative bacteria to Gram-positive ones. The interaction of nitrogen and lime restrained the adverse effects of applying nitrogen and lime separately alone on microbial biomass. PLFA in all groups of soil microbes increased with decreasing nitrogen deposition. The structural equation model (SEM) shows that the effect of liming was much stronger on the microbial community. Simulated nitrogen deposition and liming jointly through interaction affected soil pH, nutrient availability and competition for nutrient between soil microbes and plants, thus altering structure and diversity of the soil microbial community.【Conclusion】This study demonstrates that the interaction of nitrogen and lime could improve rhizosphere soil environment, mitigate soil acidification, increase soil productivity, promote microbial growth and maintain stability of the microbial community structure and diversity in fallow red soil. In conclusion, application of lime can offset the adverse impacts of atmospheric nitrogen deposition on soil microbial community by improving the habitat of fallow red soil, alleviating damage to the soil microbial community in rhizosphere and promoting restoration of the soil ecosystem.