The extracts of Quercisemen(Quereus acutissima Carruthers seed) powder was obtained by the extraction with distilled water, water : acetonet(1:1, v/v), ethanol and ethyl ether, respectively. As a result this experiment, the antioxidative activity of each solvent extracts on linoleic acid were examined as follows: 1. Each fraction extracted by the acetone : water(1:1, v/v), water and ethanol respectively showed high antioxidative activity. 2. A fraction of the tannin extracted from the solvent, acetone, water(1:1, v/v) showed even more antioxidative activity than that of the ${alpha}$-tocopherol or BHT. 3. Acceleration of peroxide reaction by $Fe^{++}$ and $Cu^{++}$ on the linoleic acid was strongly inhibited by adding the tannin, 4. Organic acid, such as malic acid, citiric acid and tartaric acid with the tannin were showed the synergistic effect fo the antioxidation reaction.