Abstract: The comparative trials on 6 popularly planted flue-cured tobacco cultivars in Yunnan were conducted under different ecological conditions.The results showed that the effects of ecological conditions on the growth vigor of tobacco plants, yield and output value, the contents of chemical components and aroma constituents, and smoking quality of tobacco leaves were more significant than that of cultivars.Therefore, reasonably locating tobacco growing areas is one of key measures for producing quality tobacco leaves.