Abstract: ObjectiveThis study compared the effects of decapitation and bagging on maturity process and smoking quality of tobacco upper leaf,and discussed the feasibility of replacing traditional decapitation with bagging,in order to provide theoretical and practical basis for developing a topping-inhibiting measure.MethodThe experiment was con-ducted in field. Tobacco plants were decapitated or wrapped by plastic bag at initial flowering stage,the changes of axil-lary bud occurrence,angle of stem to upper leaf,and contents of auxin(IAA),abscisic acid(ABA),starch and soluble sugar in upper leaf under different treatments were analyzed. The chemical constituents and smoking quality of flue-cured tobacco upper leaves were evaluated.ResultCompared to those under decapitation treatment,the tobaccos under bag-ging treatment presented weaker axillary bud growth vigor,larger angle of stem to upper leaf. In the leaves,soluble sugar content increased,starch content decreased,IAA and ABA contents increased,and maturity process of upper leaf accelera-ted. In addition,the contents of nicotine and chlorine decreased significantly(P<0.05,the same below)while the content of total sugar,reducing sugar,total nitrogen and potassium increased in upper leaf under bagging treatment. Its aroma fla-vor and taste greatly improved. The total score of sensory evaluation(39.8)was significantly higher than that of decapita-tion group(36.5).ConclusionBased on comprehensive consideration of the usability and quality of tobacco upper leaf, bagging is better than decapitation. It is feasible to replace decapitation with bagging in tobacco planting.