Abstract: The purified condition of flavonoids from seed shell of Juglans mandshurica was investigated by macroporous resin, and antioxidant activity of flavonoids were evaluated.Absorption and desorption of macroporous resin on flavonoids were investigated as recovery yield of total flavonoids as index.Additionally, scavenging ability of flavonoids on ABTS+·, DPPH·, ·OH and chelating effect on ferrous ions were determined by spectrophotometry to evaluate antioxidant activity.Results showed that using HPD-600 resin to purify flavonoids from seed shell of Juglans mandshurica, the optimal conditions were as follows:quantity of liquid sample 1/3BV, time of absorption 2h, pH6, concentration of liquid sample 1.2mg /mL, bed of macroporous resin were eluted using 4BV distilled water and 2BV 90% ethanol, purity of flavonoids was increased from 18.6% to 37.7%.Flavonoids from seed shell of Juglans mandshurica could significantly scavenge ABTS+·, could scavenge DPPH· and ·OH, and had chelating effect on ferrous ion, there were dose-effect relationship.Compared with VC, Na2EDTA and BHT, antioxidant activity was stronger than BHT, weaker than VC and Na2EDTA.Flavonoids from seed shell of Juglans mandshurica had significantly antioxidant effect.