Objective To study the optimal extraction technical parameters of total flavonoids from Oroxylum indicum by ultrasonic-assisted extraction. Methods Single-factor analysis and orthogonal design with baicalin as a standard were used to review and optimize the extraction process according to extraction yield of total flavonoids in the same conditions. Results The order of factors which affected the flavonoids extraction was time of ultrasonic treatment > ultrasound power > ratio of liquid to material > ethanol...