The antioxidant capacity of methanolic crude extracts of Berberis vulgaris L., Cornus mas L. and Mahonia aquifolium Nutt. was tested with the thiobarbituric acid reactive substances formation assay, the ferric reducing power (FRAP) and 2,2-diphenyl-2-picrylhydrazyl (DPPH•) radical scavenging assay. The content of antioxidant components in the extracts, their partition coefficient on 1-octanol:water and affinity for liposome membranes were also determined. The results show that the parameter IC50 connected with antioxidant activity on phosphatidylcholine liposome membrane decreased as follows: B. vulgaris (0.14±0.01 mg/mL) > M. aquifolium (0.34±0.03 mg/mL) > C. mas (1.13±0.01 mg/mL) for AAPH induced oxidation and M. aquifolium (0.29±0.03 mg/mL) > C. mas (1.24±0.07 mg/mL) > B. vulgaris (1.50±0.05 mg/mL) for Fe(II)/ascorbic acid induced oxidation, and M. aquifolium (2.35±0.10 mg/mL) > B. vulgaris (2.69±0.04 mg/mL) > C. mas (6.17±0.06 mg/mL) for UVC irradiation. All the extracts exhibit the ability to quench DPPH• and to reduce the ions Fe(III) to Fe(II) on the redox way. The content of active components in the extracts, partition coefficient and the extracts affinity to membranes correlated well with their antioxidant activities. Studies have shown that fruits of B. vulgaris, M. aquifolium and C. mas, from which the extracts were obtained, are attractive for consumption and can potentially be used in production of new processed fruit.