1,1-diphenyl-2-picrylhydrazyl(DPPH) radical scavenging,[2,2′-azino-bis(3-ethylbenzothiazoline)-6-sulphonic acid] diamonium salt(ABTS) radical scavenging and ferric reducing antioxidant power(FRAP) assay were used to analyze the antioxidant activity of the fruits of blackberry(Shawnee) in vitro with BHA and BHT as positive controls.The antioxidant activities of n-butanol extract from the fruits of blackberry was good.DPPH and ABTS radical scavenging activity of n-butanol extract(IC50=8.44 and 4.55 μg/mL,respectively) were higher than that of BHT(IC50=18.71 and 7.72 μg/mL,respectively),and weaker than that of BHA(IC50=3.2 and 1.88 μg/mL,respectively).DPPH and ABTS radical scavenging activity of ethyl acetate extract(IC50=38.55 and 17.25 μg/mL,respectively) were weaker than that of BHA and BHT,ethyl acetate extract and n-butanol extract exhibited weaker ferric reducing antioxidant power(Trolox equivalent=711.57±10.14 and 628.4±11.30 μmol/g,respectively) than that of BHA and BHT(Trolox equivalent=6633.04 ±114.04 and 1581.68±97.41 μmol/g,respectively).