Abstract: Objective:To optimize the reaction system of α-amylase by single-factor optimization and by response surface methodology. Methods:Based on single factor experiment using starch as substrate of α-amylase,and regarding the soluble starch concentration,the α-amylase concentration and the reaction time as three major factors,the Box-behnken design experiment was used to optimize the reaction system conditions of α-amylase and to study the influence of these factors and their interaction on the reaction rate of α-amylase. Results:The optimizing system parameter were as follows:soluble starch 12.0 mg/mL,α-amylase 1.50 U/mL,and reaction time 10.0 min. Under the conditions,the reaction rate of α-amylase was up to(19.53±1.74) mmol/(L·min). This result was near the predicted value of 18.75 mmol/(L·min)in the optimal model. Conclusion:The optimal method of reaction system of α-amylase is reliable and practical significantly for making α-amylase play an excellent activity,which to some extent lays the foundation for the study of glycosidase inhibitors efficiently under the optimal system.