We have studies fatty acid composition of water extracts of parts of omija (Schizandra chinensis Baillon) and antioxidant activities of fractionated omija parts (fruits, endocarps, seeds) were determined by DPPH methods and by in vitro hepatic microsomal lipid peroxidation system. Fatty acid composition was not different by parts of omija and major fatty acids are linoleic, oleic, and palimitic acids, among fatty acids is water extracts of parts of omija, linoleic acid was highest in content. Methanol and buthanol fractions of seeds and ethyl acetate fraction of endocarps showed stronger antioxidant activities by DPPH methods. Methanol and buthanol fractions of seeds also showed on inhibitory effect on in vitro liver microsomal lipid peroxidation.