Abstract: We analyzed the main chemical components in middle leaves of the flue-cured tobacco in Enshi of the year 2008 and 2009. The results showed that the differences of quality suitable range index was little between 2008 and 2009. The average quality suitable range index are as follow: reducing sugar 27.20%-30.54%, total sugar 32.03%-36.30%, totalalkaloids 2.20%-2.76%, total nitrogen 1.66%-1.99%, the difference between the total sugar and reducing sugar 3.73%-6.88%, the ratio of reducing sugar to total alkaloids 10.29-13.35, the ratio of total sugar to total alkaloids 12.12-15.88, the ratio of reducing sugar to total sugar 0.81-0.89, the ratio of total sugar to total nitrogen 16.46-21.48, and the ratio of reducing sugar to total nitrogen 14.09-17.93. Compared with Guizhou, Shandong and Yunnan province, the chemical components and ratios in Enshi were at middle level, and the reducing sugar, total sugar, total alkaloids, the difference between the total sugar and reducing sugar, the ratio of reducing sugar to total alkaloids and the ratio of reducing sugar to total sugar were closed to Yunnan province. The chemical components and ratios of the flue-cured tobacco middle leaves in Enshi were harmonious, which meets the requirement of high quality tobacco leaves.