In the present study, we assessed the effect of the PPA (Polygala japonica Houtt., Polygala tenuifolia WILLD. and Acorus gramineus SOLAND. mixed preparation), a traditional herbal prescription, on the learning and memory impairments induced by scopolamine. The cognition-enhancing effect of PPA was investigated using a passive avoidance test, Y-maze test and the Morris water maze test in mice. Drug-induced amnesia was induced by treating animals with scopolamine (1 mg/kg, i.p.). A single PPA (400 and 800 (mg/kg)) administration significantly reversed the scopolamine-induced cognitive impairments in the passive avoidance test (P<0.05). On the Y-maze test, PPA (400 and 800 (mg/kg)) also significantly reversed scopolamine-induced cognitive impairments in mice (P<0.05). PPA also improved escape latencies in training trials and increased swimming times and distances within the target zone of the Morris water maze (P<0.05). These results suggest that PPA attenuates amnesic state induced by scopolamine and that these Effect are mediated by enhancing the cholinergic dysfunction.