Objective: To provide a reference for resource development of Oldenlandia diffusa by optimize extraction process of total flavonoids from this medicinal herb. Method: Extraction time

ethanol concentration and amount were selected as independent variables

overall desirability of contents of rutin

isoquercitrin and quercitrin as dependent variable

Box-Behnken design-response surface methodology was used to optimize extraction technology.HPLC-DAD was adopted to determine contents of rutin

isoquercitrin and quercitrin with mobile phase of acetonitrile (A)-0.05% phosphoric acid solution (B) for gradient elution and detection wavelength of 254 nm. Result: Optimal extraction process was as following:extracted 2 times with 14-fold the amount of 73% ethanol for 1.5 h per time.Average extracting amounts of rutin

isoquercitrin and quercitrin were 2.529

0.435

0.215 mg·g-1

respectively.Deviation between the measured and predicted value of overall desirability was -1.24%. Conclusion: This extraction process is stable and feasible with high prediction accuracy

which can provide a reference for preparations development of total flavonoids from O. diffusa.