Abstract: To clarify the differences in quality characteristics among Deyang air-cured(cigar) tobacco(DX) and sun-cured tobacco(SY) and Leshan sun-cured tobacco(LS) in Sichuan province, seven cultivars were selected as experimental materials, namely Deyang air-cured tobacco cultivars "Dexue No. 1"(DX1) and "Dexue No. 3"(DX3), Deyang sun-cured tobacco cultivar "Shiyan No. 1"(SY1) and Leshan sun-cured "Nie'er Qing Qingmao"(NQ), "Nie'er Qing huangmao"(NH), "Yu'er Yan Qingmao"(YQ), and "Yu'er Yan Huangmao"(YH). The fermented tobacco leaves were systematically analyzed. The results showed that DX leaves were mainly light brown and reddish brown with a loose structure, SY leaves were reddish brown with a loose structure, while LS leaves were mostly reddish brown and dark brown with a compact texture. The single-leaf weight, specific leaf weight and leaf thickness of DX were lower than those of LS. DX leaves were characterized by relatively low contents of nicotine and potassium, while SY1 had higher contents of total sugar, nicotine and potassium. Large differences were observed among LS cultivars, with NQ and NH showing higher potassium-to-chlorine ratios. DX was mainly characterized by bean-like scents, SY1 by bean-like and woody scents, while LS exhibited typical woody and earthen scents. In terms of aroma components, DX and SY were significantly enriched in carotenoid degradation products such as 3-oxo-α-ionol, which contributed floral and woody scents and enhanced the aromatic complexity of tobacco leaves. SY was also significantly enriched in the terpenoid degradation product (Z)-3, 7, 11-trimethyl-2, 10-dien-1-ol and the cembranoid degradation product sclareol. Overall, carotenoid degradation-related metabolites were more abundant in DX and SY, cembranoid compounds were significantly enriched in SY, and the contents of terpenoid degradation products were higher in LS. These differential metabolic pathways jointly contributed to the distinct quality styles of air-cured tobacco and sun-cured tobacco from the two regions. This study elucidates the quality differences and metabolite basis of air-cured and sun-cured tobacco from Deyang and Leshan, providing a theoretical reference for the targeted development and utilization of local characteristic tobacco leaves.