Abstract: For improving the quality of upper leaves of flue-cured tobacco, five chemicals, including malic acid, citric acid, sucrose, boric acid and H₂O₂, were sprayed respectively on the upper leaves before flue-curing, and the appearance quality, chemical component contents and smoking quality of the leaves were analyzed. The results showed that the proportion of orange leaves increased obviously by chemical spraying;there was no significant effects on the chemical component contents and smoking quality by spraying malic acid (10 g per stick) and citric acid (5 g per stick);the aroma volume and the quality level were improved by spraying sucrose (20 g per stick) and boric acid (2 g per stick);the content of nicotine reduced remarkably, petroleum ether extracts increased significantly, and quality of aroma and quality level were also enhanced by spraying H₂O₂ (2 mL per stick).