Abstract: 【Objective】To study the effects of different fermentation methods on the quality factors of Deyang cigar core tobacco in Sichuan during the accumulation and fermentation process, and to provide technical reference for improving the quality of domestic cigar tobacco.【Method】During the fermentation process of cigar core tobacco leaves, nonturning(T1) and turning-processed(T2) tobacco leaves were collected.The significant difference of multiple data was used to analyze the dynamic changes of the physical characteristics, chemical components and neutral aroma substances of the tobacco leaves, and evaluation of sensory quality of tobacco leaves after fermentation was conducted.【Result】During the fermentation process, the highest temperature of the pile was 46.5℃, and the temperature of the T1 and T2 piles were 39.5 and 38.5℃respectively on day 21 of fermentation, and the moisture contents were 19.1% and 18.7% respectively.During the fermentation process, the leaf weight and thickness of the tobacco leaf showed a downward trend, and the leaf weight and leaf thickness on day 20 in T2 treatment were significantly higher than that of the T1 treatment(P< 0.05, the same below);the tensile force during the fermentation process increased first and then decreased, and the tensile force of the T1 treatment on day 10 of fermentation was significantly higher than T2.Before fermentation, the total sugar and reducing sugar contents of eggplant core tobacco leaves were low, and the total sugar content of T2 treatment was significantly higher than that of T1 treatment on day 5 of fermentation.After fermentation to day 20, the content of chlorine, total nitrogen and protein of T1 treatment tobacco leaves was significantly higher than that of T2 treatment, and potassium content of tobacco leaves in T2 treatment was significantly higher than that of T1 treatment.The carotenoid degradation product has the highest content on about day 15, and the contents of farnesyl acetone, β-damascenone, macrostigmine 2 and macrostigmine 4 in T2 treatment were significantly higher than that in T1 treatment;the browning reaction product of T2 treatment was fermented on the day 10, it was significantly higher than the T1 treatment.The furfuryl alcohol and 5-methylfurfural content were the highest on day 15 of fermentation.During the fermentation process, the phenylalanine conversion product showed a trend of first increasing and then decreasing, and the fermentation to day 20, benzyl alcohol, phenethyl alcohol and phenylacetaldehyde in T2 treatment were significantly higher than that of T1 treatment.The content of solanone in T2 treatment for 10-20 d of fermentation was significantly higher than that of T1 treatment, and the contents of benzyl alcohol and phenylacetaldehyde reached the maximum after 15 d of fermentation.After 20 d of fermentation, tobacco leaves smoke in T2 treatment had outstanding sweetness, irritation and impurities were reduced, with charred sweet aroma, mellow sweet aroma, comfortable aftertaste, and the balance of combustible and smoking indicators was better than T1 treatment.【Conclusion】During the fermentation process, the dumping treatment can increase the content of neutral aroma substances in cigar core tobacco leaves, reduce the fumes and irritation of tobacco leaves, and obtain cigar tobacco leaves with better aroma and taste.