Abstract: Oral administration of L-malate 600 mg·kg^-1 for 5 days before training cansignificantly promote memory acquisition,consolidation and retrieval,respectively,on anisodine-,chloramphenicol-,and ethanol-induced memory impaiiment in mice,Ketamine(8.5mg·kg^-1,ip),aselective NMDA receptor antagonist,was found to inhibit the anti-amnesic activity of L-malate. Theglutamate(Glu)and GABA content in mice brain was measured by high-perfonnance liquidchromatography with fluorescence detection. The content of GABA was shown to be decreased frOm2.3±0.5umol·g^-1 to l.3 ±0.5 umol·g^-1 (P<0.01),sO the Glu/GABA ratio was increasedsignificantly. These resuIts suggest that the decrease of cerebral GABA Ievel and the increase of Glu/GABA ratio is favorable to learning and memory.