Abstract: To clarify the structural and metabolic changes in microbial communities in the rhizosphere soil of healthy and black-shank-infected tobacco plants, soil samples from Nanzheng District, Hanzhong City, Shaanxi Province were analyzed by microbial metagenomics and metabolomics techniques. The results showed that：1）there was no significant difference in the diversity of microbial communities in the rhizosphere soil between healthy and infected tobacco plants, while the richness of microbial communities in the rhizosphere soil of infected tobacco plants was significantly higher than that of healthy plants. 2）The relative abundance of genera such as Caulobacter, Dokdonella and Afipia in the rhizosphere soil of infected tobacco plants was significantly higher than that of healthy plants, while the relative abundance of genera such as Acinetobacter and Arthrobacter was extremely significant or significantly lower. 3）Analysis results of 213 significantly differential metabolites revealed that the relative abundance of sugars such as melibiose, stachyose, levan and α-lactose, and amino acids such as L-leucine, L-isoleucine and valine in the rhizosphere soil of infected tobacco plants was significantly higher than that of healthy plants, while the relative abundance of organic acids such as succinic acid, nonanoic acid, 3-hydroxy-tetradecanedioic acid and salicylic acid was significantly lower. 4）Correlation analysis results indicated that the relative abundance between metabolites such as stachyose, levan,  valine and Acinetobacter, Arthrobacter in the rhizosphere soil of healthy and infected tobacco plants were highly significantly or significantly negatively correlated. Therefore, infection of tobacco plants with black shank altered the composition of metabolites in rhizosphere soil, indirectly affecting the microbial community structure and soil microecological balance.