In order to scientifically assess the chemistry of tobacco leaf, 9 chemical indices (including nicotine, total sugar, reducing sugar, total nitrogen, potassium, chlorine, sugar/nicotine ratio, nitrogen/nicotine ratio and potassium/chlorine ratio) of B2F, C3F, X2F leaves of varieties Yunyan87, K326, Yunyan97 and Yunyan85 sampled from the tobacco production bases A, B, and C of China Tobacco Jiangsu Industrial Corporation in Yunnan were analyzed. The usability of tobacco leaf was analyzed by means of fuzzy judgment, and the similarity of chemical indices between Zimbabwean and domestic flue-cured tobacco leaves was compared by calculating Euclidean distance coefficients. The results showed that: 1) The average contents of nicotine (2.29 %), chlorine (0.37 %), total nitrogen (2.85 %) and the ratio of potassium to chloride (5.74) in the samples were within suitable range, while those of the other five chemical indices were slightly lower or higher. 2) The mean value of chemical usability index of the samples was 0.58, which indicated that chemically the overall quality was close to moderate level. 3) Chemically the domestic samples and Zimbabwean flue-cured tobacco leaves of the same stalk positions was of moderate similarity, the similarity of leaves from Production Base B was the lowest. 4) For B2F and X2F grades of different varieties, the average similarity distance coefficients of Yunyan 87 were the biggest, while for C3F, that of K326 was the biggest. 5) The correlation between chemical usability index and similarity distance coefficient reached significant level. The two methods were compatible to a certain extent for studying the quality of flue-cured tobacco.