Abstract:The study was aim to find the best technology conditions in extracting rutin from Sophora japonica，ultrasonic-assisted extraction technique was used as extraction method.In the research，the extraction rate of rutin in the Sophora japonica was selected as the index，and the ratio of liquid，the time and the number of times of ultrasonic extraction were used as influencing factor.On the basis of single factor experiments，three factors，three levels，and the principle of BBD center combination were applied in the experiment.The extraction conditions were optimized by the method of RSM.The result was that rutin extraction rate was 17.96%when the material liquid ratio was 1∶16（g/mL），the ultrasonic extraction time was 20 min and the times was twice.The disparity with the Design-Expert.V8.0Analysis prediction maximum extraction rate（18.09%）was minimal.Through experimental verification，the result showed that the response surface method of optimizing conditions of extracting rutin in the Sophora japonica was feasible when RSD was 1.15%.