A study analyzed 163 samples of flue-cured tobacco from Xuanwei to determine the main chemical factors affecting flavor and quality. They found that total sugar, reducing sugar, nicotine, total nitrogen, and other chemical levels influenced the flavor and quality grade of the tobacco. Factors like petroleum ether extracts, starch, and copper content also played a role. The study identified specific ranges for key chemical indexes that result in high-quality tobacco with a characteristic flavor, such as total sugar between 26% to 40% and nicotine between 1.2% to 2.4%. These findings help in understanding how different chemical components impact the taste and quality of tobacco leaves from Xuanwei.