Abstract:The flavonoids in tartary buckwheat was extracted by 70 % ethanol， and using macroporous resin pu－ rified the flavonoids. The antioxidant effect of DPPH， ABTS and hydroxyl free radical three methods were used to detect the effect of the purified and unpurified on the flavonoids from tartary buckwheat. The results showed that purified and unpurified of the flavonoids in tartary buckwheat had the ability of antioxidation， and it was positively correlated with the concentration of flavonoids. In the scavenging action of DPPH free radical， the clearance rates were 41.8 % and 61.6 % ， respectively， when the concentration of purified and unpurified flavonoids was 0.005 %；the clearance rate of ABTS was 54.7 % and 61.1 %， respectively， when the concentra－ tion of purified and unpurified flavonoids was 0.005 %； in the scavenging effect on OH free radical， the concen－ tration of purified and unpurified flavonoids was 0.1 %， and the removal rate was 14.7 % and 10.3 % respec－ tively. The antioxidation effect for DPPH free radical and ABTS free radical， the purified flavonoids was weaker than the unpurified of flavonoids； to hydroxyl free radical， the purified flavonoids was stronger than the unpuri－ fied of flavonoids.