Accumulation of peroxidized lipid, fed or injected in the body of rats was investigated and the effect of peroxidized lipid on the antioxidative system was studied also. Three groups each having six of Sprague-dawley rats were raised for 8 weeks. the peroxide value(POV) of diet fed to the control and the peroxidized group was 5.47 and 22.14meq/kg , respectively. Injected group was given the control diet and peroxidized linoleic acid(POV 31.81meq/kg) was injected into the peritoneal area three times a week. The POV, MDA, and protein carbonyl values of the peroxidized and the injected group (experimental groups) were significantly higher (p<0.05) than those of the control group. Cu, Zn-SOD and M-SOD activity of the experimentla groups increased 1.6 times that of control group at 4 th week. and decreased by 60% of their activityafter 8 weeks of feeding (p<0.05) . Catalase activity, glutathione and Vt, E contents of the experimental groups were significantly lower (p<0.05) than those of the control group during 8 weeks. The accumulation of peroxidcized lipid in liver were ovserved both in the fed or the injected group. The increased of enzyme activity of the experimental group during 4 weeks suggests ianadaptation of antioxidative system to get rid of the peroxidized lipid. Decrease of enzyme activity and glutathione observed as the peroxidized lipid lipid accumulation proceeded further, however, seems to indicate the oxdiative damage of enzyme and protein . Determination of the protein carbonyl content may be used as a method for measuring the oxidative damaging effect of peroxidized lipid.