Abstract: Objective: Establish a method of ultrasonic assisted extraction of flavonoids in Gueldenstadetia verna. Method: The whole plant of Gueldenstadetia verna as experimental material, do experiment by selecting four single factors: solid-liquid ratio, ultrasonic temperature, ultrasonic power, extraction time, on this basis, through these four single factors as the independent variable and the yield of total flavonoids of Gueldenstadetia verna as response values, design the response surface optimization method of four factors three levels. Results: The best process parameters for optimization analysis are as follows: ratio of solid-liquid 1:40 g/mL, ultrasonic temperature 45 ℃, ultrasonic power 300 w and ultrasonic time 60 min. The actual value was 8.0795 %, compared with the theoretical value 8.2195 %, the RSD was 0.33%. Conclusion: This experiment method have advantages of simple operation, short extraction time, solvent recovery and low cost, and the component have the advantages of quality, less solvent residue.