Abstract: To improve the quality of upper leaves, six upper leaves of K326 was sprayed with a microbic agent, which was prepared with beneficial microorganisms (identified as Bacillus negaterium) isolated from the soil in tobacco field, by 750 and 1500 milliliters/ha on 10th day before harvesting.The leaves were harvested upon ripeness, the cured leaves were chemically analyzed and evaluated by panelists.The results indicated that the contents of important flavor components in the leaves increased obviously, amino acids and protein reduced slightly, and smoking quality was significantly improved comparing with the control.