Chaenomeles speciose Nakai (CSP) or Chaenomeles sinensis Koehne (CSS) (Rosaceae) has been used, traditionally, to treat muscle problems and gastric dampness in eastern Asia countries. Therefore, many studies have focused on investigating its active compounds and effects on muscle pain, arthritis and gastro-intestinal diseases. Recently, several studies reported that CSS extract degrade amyloid plaques and enhance synaptic acetylcholine level in vivo and in vitro. Although these two Chaenomeles species are used without differences, CSP is reported to contains more phenolic compounds which are known to enhance memory. Therefore, in this study, we investigated the memory ameliorating effects of CSP by employing the passive avoidance test, Y-maze task and novel object recognition test. CSP (30 or 100 mg/kg) ameliorated the declined memory induced by scopolamine injection and enhanced the brain-derived neurotrophic factor (BDNF) levels along with post synaptic density protein 95 (PSD 95) levels at the hippocampus of the scopolamine-injected mouse brain. These results suggested that CSP alleviates the cognition declines caused by cholinergic blockade via enhancing BDNF levels and PSD 95, and that it would enhance memory formation and be useful for treating memory declines.