Abstract: To clarify the quality characteristics differences between Deyang air-cured tobacco (DX), sun-cured tobacco (SY), and Leshan sun-cured tobacco (LS), seven varieties of tobacco leaves, including Deyang air-cured 'Deyue No. 1' (DX1), 'Deyue No. 3' (DX3), Deyang sun-cured 'Shiyan No. 1' (SY), and Leshan sun-cured 'Nie'er Qingqing Mao' (NQ), 'Nie'er Qinghuang Mao' (NH), 'Yuer Yanqing Mao' (YQ), 'Yuer Yanhua Mao' (YH) were selected for a systematic analysis of the cured and fermented tobacco leaves. The results show that: DX tobacco is primarily red-brown, with a loose leaf structure, while SY is light brown, also with a loose leaf structure, and LS is mostly brown with a firm texture; DX's single leaf weight, leaf weight, and leaf thickness are all lower than those of LS; the nicotine and potassium-to-chlorine ratio in DX tobacco are significantly lower than those in SY and LS, while DX's total sugar, reducing sugar, and chlorine content are similar to some varieties of LS, and SY has higher total sugar, nicotine, potassium, and potassium-to-chlorine ratio than DX; DX's flavor is mainly nutty and bean-like, SY is characterized by bean and woody scents, while LS has a typical woody and earthy odor. In terms of aroma components, DX and SY both significantly accumulate carotenoid degradation products such as 3-oxo-α-violet alcohol, which bring floral and woody scents and enhance the complexity of tobacco aroma; SY also significantly accumulates terpenoid degradation products such as nerolidol and cedrol. DX is more enriched in carotenoid degradation products, while SY significantly accumulates cedrol-type compounds, and LS shows significantly higher levels of terpenoid-related metabolites. These differential metabolic pathways collectively determine the quality and style of the tobacco in these regions. The study results elucidate the quality differences between Leshan and Deyang sun-cured tobacco and their metabolic basis, providing theoretical support for the targeted development and utilization of local characteristic tobacco leaves.