Abstract: In order to explore the effects of different organic manures on microbial diversity in tobacco growing soil, a long-term stationary field experiment was conducted to study the effects of different organic manures on the functional diversity and soil fertility of tobacco-planting yellow-brown soil, in which the fertilization treatments included chemical fertilizer (CK), chemical fertilizer with commercial organic manure (CFM1), chemical fertilizer with farm manure (cow manure, CFM2) and chemical fertilizer with green manure (Viciavillosa Rothvar, CFM3). The results showed that the microorganisms' carbon utilization ability at prosperously growing stage was higher than that of resettling, maturing and harvested stages. Compared with CK, the average well color development (AWCD) of the CFM1 and CFM2 treatments significantly increased by 22.0% and 31.0%, respectively. The Mclntosh diversity index increased 15.2% and 18.0% at resettling stage. AWCD and functional diversity indices of CFM1 at prosperously growing stage were significantly higher than others. Organic manures application led to an increase of 19.9%-37.4% of labile organic carbon and an increase of 11.9%-21.0% of microbial biomass carbon comparing to CK. The 8-years organic manure application improved soil pH, organic matter, alkaline nitrogen and available potassium in some extent. However, CFM1 showed the highest pH value comparing to CFM2 and CFM3. The pH value and available potassium were significantly positively correlated with microbial functional diversity. In conclusion, the chemical fertilizer applied with commercial organic manure could have better promoting effects on microbial metabolic activity and soil fertility.