According to the principles，the influences of conditions of the maillard reaction, such as reaction time and ratios of exogenous amino acids to sugars, on the improving effects of tobacco sheets were evaluated. The results showed that when the initial pH being 7.0～8.0 and thermal reaction temperature of 70 ℃, the optimum conditions for maillard reaction of extracts were as follows: reaction time of 13h, and the ratios of exogenous amino acids to carbohydrates being Pro︰Gly︰Phe︰Cys︰peptides︰fructose as 13︰13︰13︰2︰0.3︰70. GC—MS was used to analyze the main flavor components of the reaction mixture, and the tobacco sheet samples were sensory evaluated by professionally smoking group. Flavor components, such as Furfural and Megastigmatrienone were effectively increased via Maillard reaction, and unfavorable adverse ingredients of tobacco sheets, such as 5-Methyl-2-furanmethanol and Lauryl ether, were significantly reduced. Therefore, the maillard reaction is an effective method to improve the quality of tobacco sheets.