This study was performed to investigate the effect of acorn supplementation on the lipid profile and redox antioxidant enzyme activities in obese rat. Obesity in the rats was induced by feeding diet contained 10％ lard and 0.5％ cholesterol for 4 week. After 4 weeks, rats were divided into the following 5 groups; high fat diet (Control), high fat diet plus 10％ Acorn powder (APlO％), high fat diet plus 20％ Acorn powder (AP20％), high fat diet plus 0.2％ Acorn extract (AE0.2％), high fat diet plus 0.5％ Acorn extract (AE0.5％). Total food intake and food efficiency ratio (FER) was not significantly different by acorn powder and extract supplementation. But, body weight was decreased by 20％ acorn powder. Acorn powder and extract supplementation for 4 weeks tend to decrease total cholesterol and triglyceride level on the serum and hepatic tissue. There was no significant difference in hepatic glutathione (GSH) content among all the groups. The hepatic GST activity in acorn supplemented groups was lower than that of control. Glutathione peroxidase and catalase activities were higher in acorn supplemented groups than that of control. Hepatic TBARS levels of experimental groups were also significantly lower than that of control group. Our finding suggest that acorn powders and extract might have potential role for improving lipid profiles and antioxidant enzyme activities in obese rats.