This study has examined the effects of Aralia elata Seemann ethanol extract on antioxidant enzyme systems inrats along with benzo($alpha$) pyrene(B(a)P) administration . The ethanol extract of Aralia elata Seemann (50mg/kg body wt.) was fed to rats for 4 weeks by stomach tubing. The extract administration increased antioxidant activities of glutathione sulfur transferase(GST) comparing to the control. also total superoxide dismutase(SOD) and Cu, Zn-SOD activities were stimulated. Catalase activities were increased by 50% with the extract feeding compared to the control . Combined administration of B($alpha$)P and the extract increased GST activity in B($alpha$) P group. Although total SOD acitivity was decreased , Cu, Zn-SOD was greately increased from 0.10unit to 0.18 unit and catalase activity also was increased compared to the group of B($alpha$) P. GST activity in CLE group was 1.32 unit, increased by 33% comparing to the group CL of 0.99unit. Cu, Zn-SOD and catalase activities in thegroup fed high fat and ethanol extracts were increased by 25% and 39%, respectivley comparing to the group of high fat. In addition , total SOD was decreased but, Cu, Zn-SOD acitivity was increased from 0.09 unit to 0.18unit. Catalase activity was 76.05 unit in the group of B($alpha$) P and extract comparing to 65.26 units in B($alpha$)P group. Serum $alpha$-tocopherol of rat was markedly increased by theextract. Administration of B9$alpha$)P reduced $alpha$-tocopherol levels in the serum, on the other hand, lard in the diet increased $alpha$-tocopherol levels in the serum. The above results indicate that Aralia bud exerts antioxidant functions in vivo against B($alpha$)P. Further research may be necessary for the identification fo the biologically active material.