The Ablmoschus manihot (L.) Medic, an edible hibiscus of the Malvaceae family, is abundant with total flavonoid. The content of total flavonoid from A. manihot flowers (TFA) was extracted by 70% ethanol (ethanol:water, 70:30). The scavenging effects of TFA on superoxide anions and hydrogen radicals were related to the total flavonoid concentrations with the IC50 values of 63.90 ±2.21 μg/mL and 266.88±28.32 μg/mL, respectively. However, the IC50 values of standard ascorbic acid were 436.52 ±14.36 μg/mL and 439.58±21.41 μg/mL, respectively. The DPPH radical scavenging activity increased with increasing of TFA concentrations and the highest inhibition was 94.63 ±3.01% at 50 μg/mL, as compared to ascorbic acid 34.94 ±1.50%. The extract also showed good reducing power. The data from this study suggest A. manihot flower extract has significant potential to use as health supplements and nutraceuticals.