This research employed a senescence-accelerated mouse(SAM) to explore the possibility that differences exist among the major antioxidatns, lipid peroxidation in terms of ability to protect such animal treatment PQ, SAM-R/1 and SAM-P/8 were administered with PQ(200ppm/Kg) orally. The toxicity of PQ on SAM was determined as a bioassays of SOD, catalase and lipid peroxidation in the mouse liver. The data show that the SOD activity was induced by paraqwuat terement in both SAM-R/1 and SAM-P/8. The degree of lipid peroxidation was increased with PQ treatment. This means that SOD rather than catalase may protect against oxygen radical toxicity. Finally, over data lead to the toxicity of PQ and its function may efect to the antioxidants including SOD, catalase and lipid peroxidation in both SAM-R/1 and SAM-P/8 .