Response surface methodology（RSM）was used to optimize the extraction process of Kelu oral liquid.Methods:Among the prescription，Scutellaria Baicalensis was the principal drug，and the main component，baicalin，was the index of quality control.Based on the single factor analysis，the extraction time，extraction frequency and solid-to-liquid ratio were independent variables，and the amount of baicalinwasresponse value.The research center combined the design of the experiment，studied each independent variable and its interaction effect on the amount ofbaicalin and builded Second-degree polynomials equation mathematical model of prediction.Results:The extraction time，extraction frequency and solid-to-liquid ratio had all significant effects on the amount of baicalin.The optimal technology parameters extraction time of Kelu oral liquid was 70 min，the extraction times was 2 times，and solid-liquid ratio was 1:13Under such conditions，the amount of baicalinwas 096 mg/mL.Conclusion:Box-Behnken could be used for extraction optimization of extraction process for Kelu oral liquid，and the optimized technology was quick，simple and stable，besides，it had reference value for optimization of extraction of oral liquid.