[Objectives] To optimize the extraction process of total flavonoids in stems of Mallotus apelta. [Methods]On the basis of singlefactor test,with volume fraction of ethanol,extraction time and ratio of solvent as independent variables,the content of total flavonoids as dependent variables,the completely secondary response surface regression fitting was conducted on the independent and dependent variables,and the Response Surface Method was used to optimize the optimum extraction process of total flavonoids in Mallotus apelta stems and predict the optimum process. [Results] The optimum extraction process of total flavonoids in Mallotus apelta was determined as follows: ethanol concentration of 71. 5%; extraction time of 154. 6 min; solid-liquid ratio of 1∶19. 2; total flavonoids content of 7. 060 mg/g; fitted binomial squared correlation coefficient R~2= 0. 8751.[Conclusions]Composite Design/Response Surface Method could be used in the extraction process optimization of total flavonoids in Mallotus apelta stems,the mathematical model established had high prediction accuracy,the method was simple and operability was good. [Objectives] To optimize the extraction process of total flavonoids in stems of Mallotus apelta. [Methods] On the basis of single factor test, with volume fraction of ethanol, extraction time and ratio of solvent as independent variables, the content of total flavonoids as dependent variables, the completely secondary response surface regression fitting was conducted on independent and dependent variables, and the Response Surface Method was used to optimize the optimum extraction process of total flavonoids in Mallotus apelta stems and predict the optimum process. [Results] The optimum extraction process of total flavonoids in Mallotus apelta was determined as follows: ethanol concentration of 71.5%; extraction time of 154. 6 min; solid-liquid ratio of 1:19. 2; total flavonoids content of 7. 060 mg / g; fitted binomial squared correlation coefficient R ~ 2 = 0. 8751. [Conclusions] Composite Design / Response Surface Method could be used in the extraction process optimization of total flavonoid s in Mallotus apelta stems, the mathematical model established had high prediction accuracy, the method was simple and operability was good.