This study investigated the antioxidant activities of polyphenols in black garlic. According to “health food inspection and evaluation of technical specifications”, SPF grade KM mice were randomly divided into the blank control group, model control group and black garlic polyphenols groups. The mice in the garlic polyphenols groups were treated at a dosage of 2.04,4.10, and 12.25g/(kg·bw) for 30 days. The gastric oxidative damage was induced by bromobenzene oil. The liver tissues of mice in the control group and black garlic polyphenols treated groups were taken. The MDA contents, superoxide dismutase (SOD) activities, glutathione peroxidase (GSH-Px) activities, and total antioxidant capacity (T-AOC) in liver and serum were investigated. The results showed that the contents of MDA in serum and liver tissue of mice significantly decreased, and the activity of SOD, GSH-Px and T-AOC significantly increased with the increase of the crude extract. According to the standard of health food functional evaluation procedure and test method standard, it is concluded that the crude extract of black garlic has the function of antioxidation.