Objective: To study the conditions and parameters of purifying total flavonoids from L.dunnii with AB-8 macroporous resin and to compare with antioxidant ability before and after being purified.Method:Some factors which effected purification in static and dynamic adsorptions were studied.Furthermore

the antioxidant ability were also determined.Result:The concentration of the sample solution was 0.3 mg/mL.In static adsorption

the effects were preferable when temperature was at 20～40 ℃ and pH value was 4～5 and using 70% ethanol as desorption reagent. In dynamic adsorption

pH value of sample solution was 4～5 and flowing rate of loading was 0.5～1.0 mL/min. Using 70%～90% ethanol and 0.5～1.5 mL/min flow rate

the eluting effect was good.The clearance rates of 0.12 mg/mL refined flavonoid powder and crude flavonoid powder were 78.43% and 29.25% respectively.The inhibitory rates to pyrogallol autoxidation of 0.375 mg/mL crude flavonoid powde and refined flavonoid powder were 98.49% and 63.02% respectively.Conclusion:AB-8 macroporous resin had an excellent purification effect to crude flavonoid of Lespeda dunnii.The purity and antioxidant abbility were improved remarkably.