Abstract:Aqueous two-phase extraction was applied to extract the total flavonoids in Cistanche deserticola Y.C.Ma and the antioxidant ability of the extracts in vitro was also investigated． Orthogonal tests were employed to optimize the extraction technology． The antioxidant ability of the extraction solution was evaluated according to its scavenging activity and reducing power for DPPH·and·OH． The optimal feed liquid ratio，the ratio between ethanol and water, extraction time and extraction temperature were 1 ∶ 50（g ∶ mL）, 50 % ethanol solution, 3.5 hours and and extraction temperature 90 ℃, respectively. The concentration of total flavonoids in Cistanche deserticola Y.C.Ma could reach（13.04 ± 0.06） %. The best aqueous two-phase separation system was EtOH-K2HPO4. The optimal ratio between ethanol and water, mass concentration of potassium hydrogen phosphate anhydrous and volume fraction of flavonoids extract were 0.7（mL ∶ mL）, 0.2 g/mL and 14 %，respectively． The concentration of the total flavonoids in Cistanche deserticola Y.C.Ma was enriched 2.85 times with aqueous two-phase extraction． The highest scavenging rates of total flavonoids of DPPH·and·OH were 91.8 % and 35.9 % respectively, indi－ cating that the total flavonoids scavenging effect of DPPH·on free radical was stronger than that of·OH.