Abstract: To explore the effects of fermentation media and processes on the quality of cigar tobacco, the trends of routine leaf chemical components, non-volatile organic acids, aroma components and microbial community composition in leaf samples of cigar tobacco cv. Dexue-7 were studied under water-fermentation and medium-fermentation separately. The results showed that: 1) The mass fractions of total nitrogen and alkaloids did not change significantly, while the mass fractions of total sugars and reducing sugars decreased during fermentation. 2) The mass fraction of non-volatile organic acids was affected after adding a fermentation medium, which was beneficial to reduce the astringency and irritation of cigar tobacco smoke. The composition of non-volatile organic acids in the samples fermented with the medium for 14-21 d endowed the leaf with better sensory quality. 3) The total contents of aroma components increased first and then decreased during the fermentation, and peaked during 14-21 d. Additionally, the addition of the fermentation medium promoted the accumulation of aroma components. 4) The compositions of fungal community in the samples were significantly changed by the fermentation medium. The diversity of bacteria and fungi in the samples significantly increased on the 21th day of fermentation, and abundant Staphylococcus was found during 14-21 d, which was conducive to the formation of aroma components.