AimTo study the technical process to extract ginkgolic acids in the exotesta of Ginkgo Biloba L. by ultrasonic extraction. MethodsHPLC has been adopted to determine the products. The operation conditions of extracting were optimized by orthogonal experiments.ResultsThe ratio of the exotesta of Ginkgo Biloba L. to 75% ethanol is 1∶30 and the ultrasonic extracting time is 30 minutes. The concentration of the ethanol has the greatest affect to the extraction process.ConclusionThe method can be used to obtain h...