Objective: The antioxidant activity of synthesized 3-bromo-4

5-dihydroxybenzaldehyde was studied. Method: Radical scavenging effects were determined

with 1

1-diphenyl-2-picrylhydrazyl (DPPH) radical

hydroxyl radical and superoxide anion radical respectively. Result: It was found that 3-bromo-4

5-dihydroxybenzaldehyde had obvious scavenging effect on DPPH radical activity with IC50as 4.49 mg·L-1. It was better than positive controls

Vit C and t-butyl hydroquinone (TBHQ). The scavenging ability on O-2 radical is stronger than TBHQ

with IC50=0.93 g·L-1

while on hydroxyl free radical

weaker than Vc and TBHQ with IC50=122.42 mg·L-1. Conclusion: The antioxidant activity of 3-bromo-4

5-dihydroxybenzaldehyde was obvious and could be developed to a medicine or antioxidant ingredient in food.