OBJECTIVE： To optimize reflux extraction technology of total flavonoids from the roots and stems of Angelica sinensis. METHODS： The reflux extraction technology of total flavonoids from the roots and stems of A. sinensis was optimized by Box-Behnken design-response methodology based on single factor test using volume fraction of extraction solvent ethanol， solide-liquid ration， extraction time， extraction times as investigation factors， the content of total flavonoids in extract as evaluation index. RESULTS： The optimal extraction technology of total flavonoids from the roots and stems of A. sinensis was that volume fractions of ethanol were 70％ and 50％； solid-liquid ratios were 1 ∶ 40 and 1 ∶ 30； extraction time were 1.3 h and 1.7 h； The number of extraction times is two times. In verification test， the contents of total flavonoids were 7.253 6， 25.144 1 mg/g （RSD＝1.57％， 1.49％， n＝3）； relative errors of those to predicted value （6.942 8， 25.703 5 mg/g） were 4.28％， 2.24％. CONCLUSIONS： Optimized extraction technology for total flavonoids from the roots and stems of A. sinensis is simple， reproducible and predictable.