The antioxidant activity of the red pigment was investigated in soybean phosphatidylcholine liposome membrane and sunflower oil-in-water emulsion system exposed to AAPH generated peroxyl radicals.Total antioxidant activity of the crude extract was evaluated by measurement of the ferric thiocyanate assay and thiobarbituric acid test.The results indicated that the red pigment extracted from Cerasus humilis with the concentration of 0.0016 mg/mL,0.004 mg/mL,0.008 mg/mL in soybean phosphatidylcholine liposome membrane and the concentration of 0.02 mg/mL,0.05 mg/mL,0.10 mg/mL in sunflower oil-in-water emulsion system was a chain-breaking antioxidant.It was clear that antioxidant activities of individual the red pigment extracted from Cerasus humilis decreased with the rise of their concentrations.Furthermore,synergistic interactions between the red pigment extracted from Cerasus humilis and ascorbic acid/α-tocopherol against lipid peroxidation were also investigated.It was shown that the synergistic interactions were not found in the whole experiment.