This study was carried out to study influence of antioxidants on serum and tissue of rats fed with thermally oxidized oil. The experimental animals used 30male rats of sprague-dawley weighting 150±25g. They are divided into 5 groups and fed to experimental diets which are composed of 15％ thermally oxidized oil in addition to ascorbic acid, Vitamin E, Ethylendintrioteraaceticacid(EDTA) and none added oxidized oil by heat and fresh soybean oil group. Thermally oxidized oil was prepared from the soybean oil by heating at 180℃ for 30 hours. After feeding for 4 weeks, the result are as follows; 1. Body weight gain were lower B diet group than A diet group. 2. Total cholesterol levels in serum of all experimental diet groups except B diet group were higher than that of A diet group. 3. HDL-cholesterol levels of all experimental diet groups except E diet group were lower than that of A diet group. 4. The activities of GOT, GPT in serum of all experimental diet groups except B diet group and D diet group were higher than that of A diet group. 5. Vitamin E levels in serum of E diet group were highest than that of all experimental diet groups, and Vitamin E levels in liver of A diet group were highest than that of all experimental diet groups. 6. Lipid peroxide in Serum were highest B diet group than that of all experimental diet groups and the other experimental diet group significantly lower than that of the A diet group. 7. Lipid peroxide in liver of all experimental diet group except E diet group were significantly higher than that A diet group and lipid peroxide in kidney of all experimental diet group except B diet group were lower than that of A diet group. Four these results, as Vitamin C, Vitamin E, and EDTA added diets have effect of thermally oil by antioxidants, it could be suggested that thermally soybean oil diet has required to add antioxidant because it has not sufficient Vitamin E for antioxidant and intake and overtake level of thermally soybean oil diet should be studied to go ahead.