Abstract: In the present experiments,an impairment of memory model was made by cerebral ischemia-reperefusion in mice.Sal A at the dosage of 3 and 10 mg·kg^-1iv was shown to improve the impairment of memory function induced by cerebral ischemia-reperefusion in step down and step through tests.In these tests,the number of errors of Sal A treated group was less and the latency was longer than that of control group.Meanwhile,Sal A 3 and 10 mg·kg-l iv was found to reduce the MDA contents in the cortex, hippocampus and striatum of cerebral ischemia-reperfused rats in vivo.Sal A 10～100 nmol·L^-1 was shown to inhibit the brain lipid-peroxidation and scavenge the free hydroxyl radical in vivo, These results indicate that the antagonistic effects of Sal A on impairment of learning and memory caused by cerebral ischemia-reperefusion may be related with its anti-oxidant activity.