Abstract:Objective to optimize the technology for extracting process of total flavonoids from Ginkgo biloba leaves. Methods Based on the single factor experiments for ethanol concentration, solid-liquid ratio and extracting time, orthogonal experiment L9 (33) was designed to optimize the ethanol extracting conditions of total flavonoids by ultrasonic-assisted method. Results the optimal technology for extracting conditions of total flavonoids was as followed: with 60% ethanol concentration, 1∶50 (m∶V) solid-liquid ratio and 30 min of extracting time. Conclusion According to the results of variance analysis, ethanol concentration (P<0.01) had the greatest influence on yield of total flavonoids, followed by solid-liquid ratio (P<0.05), extracting time was the minimal influence (P>0.05). Under these conditions, the yield of total flavonoids was 8.075 mg/g and the extracting rate was 80.75%.