The antioxidant activity of essential oil from flavelo and extracts from mesocarp and seed of Shatian shaddock in linoleic acid system was investigated by ferric thiocyanate method. The results showed that the inhibition of linoleic acid peroxidation of diethyl ether extract from mesocarp (DEEM) and ethyl acetate extract from seed (EAES) was w = 99.17 % and 92.55% respectively. The antioxidant activity of DEEM was higher than that of BHA and EAES was as high as BHA. The inhibition of linoleic acid peroxidation of essential oil was w =55.24%. The study results proved that antioxidant activity of DEEM and EAES was correlated with total phenolic compounds contained in them.