This study examined the effects of xanthoceraside (1) on learning and memory impairment induced in mice by intracerebroventricular injection of aggregated peptide beta-amyloid 25-35 (Abeta(25-35)). Learning and memory functions in mice were examined using step-through, Y-maze and water maze tests. Administration of 1 reduced the number of errors and prolonged latency in the step-through test in mice impaired by Abeta(25-35). Likewise, latency to find the terminal platform was decreased and the number of right reflects was increased in the water maze test, and the percentage of alternation behaviors in the Y-maze test was increased. Biochemical studies showed that decreased activities of superoxide dismutase, glutathione peroxidase, and acetylcholinesterase, and increased content of malondialdehyde in mice impaired by Abeta(25-35) were significantly ameliorated by administration of 1. The present results suggest that 1 may provide a potential treatment strategy for Alzheimer's disease.