[Objective] To study the antioxidant activity of ellagic acid from Rubuso suavissimus S. Lee. [Method] The ellagic acid was extracted and purified from R. suavissimus by solvent extraction and recrystallization, and its DPPH· scavenging ability and reducing capacity were studied by in vitro test. In addition, the total antioxidant activity of ellagic acid was determined by phosphomolybdate method. [Result] The ellagic acid could effectively eliminate DPPH· free radicals, which was characterized by fast speed, low dosage and strong antioxidant activity. When the concentration of ellagic acid was 0.10 mg/ml, the DPPH· scavenging rate reached more than 92.5%. The reducing capacity of ellagic acid was improved by raising concentration, which was lower than that of BHT at the concentration below 0.5 mg/ml and higher than that of BHT at the concentration above 0.5 mg/ml. Furthermore, the total antioxidant activity increased with the increase of concentration and with the extension of action time. [Conclusion] It is significant to develop and utilize ellagic acid with strong free radical scavenging capacity. [Objective] To study the antioxidant activity of ellagic acid from Rubus suavissimus S. Lee. [Method] The ellagic acid was extracted and purified from R. suavissimus by solvent extraction and recrystallization, and its DPPH · scavenging ability and reducing capacity were studied by In addition, the total antioxidant activity of ellagic acid was determined by phosphomolybdate method. [Result] The ellagic acid could be eliminated DPPH free radicals, which was characterized by fast speed, low dosage and strong antioxidant activity. When the concentration of ellagic acid was 0.10 mg / ml, the DPPH · scavenging rate reached more than 92.5%. The reducing capacity of ellagic acid was improved by raising concentration, which was lower than that of BHT at the concentration below 0.5 mg / ml and higher than that of BHT at the concentration above 0.5 mg / ml. Furthermore, the total antioxidant activity increased with the increase of concentration and with the extension of acti on time. [Conclusion] It is significant to develop and utilize ellagic acid with strong free radical scavenging capacity.