Intercropping has been widely practiced throughout the world because of its multiple benefits to yield advantage and ecosystem processes，especially in cereal and legume combinations.However，the effects of root interactions on soil carbon metabolism in cereal/legume intercropping are still unknown.A 2-year (2017～2018) field experiment combined with a root separation pattern experiment，three root barrier treatments，led to complete，partial and no root interactions between foxtail millet (Setaria itlica) and peanut (Arachis hypogaea Linn) in greenhouse.These two experiments were conducted to investigate the rhizosphere microbial community structure and diversity by applying biology technique.And yields of millet and peanut，land equivalent ratio (LER) were also measured under different plant patterns.Results showed that the LER was more than 1 in both plant patterns across 2 years，especially for the 2∶2 intercropping mode of millet with peanut treatment，in which the LER was up to 1.36 in 2018，which indicated that the intercropping system of cereal millet and legume peanut was a system with significant yields advantage.The biomass and yield of foxtail millet in no root interactions for pot experiment were significantly increased by 49.0% and 92.6%，for peanut，the values were 11.1% and 44.6%，respectively.The harvest index (HI) of millet and peanut was also increased significantly.Compared with the treatment of no root interactions，root interaction promoted the utilization efficiency of carbon source of rhizosphere microbes.The utilization of 31 carbon sources of rhizosphere microbes of intercropped millet and peanut was increased by 19.6% and 72.2% on average，respectively.Principle component analysis (PCA) and cluster analysis results showed that the carbohydrates and amino acids were the main and sensitive carbon sources of microbial community induced by interspecific root interactions.The functional diversity index of Shannon index and Simpson index were higher in intercropping rhizosphere soil under interspecific root interactions，even no significant difference was observed.These results would contribute to a comprehensive understanding of how interspecific facilitation (biomass accumulation，carbon sources utilization，microbial diversity) can be observed in the cereal and legume intercropping which is driven by below-ground root interactions.