The objective of this study was to evaluate their effects as the meat antioxidant and on the antioxidant enzymes like superoxide dismutase(SOD) and catalase during the refrigeration storage of ground beef, respectively. Ground beef loin was treated by three natural antioxidants(pycnogenol, catechin, ${alpha}$-tocopherol) and the synthetic antioxidant(BHT) at the level of 0.01%(w/w) of total fat. Samples were refrigerated at $4{sim}6^{circ}C$ for 3, 5, 7 and 10 days to evaluate the color and the pH as the quality parameters, TBA value and fatty acid composition as the parameters of lipid peroxidation, and the activities of SOD and catalase. This study showed that catechin and pycnogenol were excellent in terms of meat color, pH and delaying lipid peroxidation and also maintained the activity of in vivo SOD and catalase better than ${alpha}$-tocopherol and BHT. These results suggested that the duration of the refrigeration of ground beef may be prolonged up to 10 days in catechin and pycnogenol treated ones in terms of the lipid peroxidation, but 5 days of refrigeration will be more adequate if considering the microbial safety as food, too.