In this study, our aim was to clarify the ameliorative effects of zeatin, a development hormone in plants. Zeatin mitigated cognitive deficits and showed AChE inhibition in scopolamine (Scop)-induced mice following 21 d of zeatin treatment. After administration of Scop for 30 min, each mouse performed Y-maze and step-down latency tasks as a check on immediate against cognitive function. The results showed that zeatin administration attenuated Scop-induced memory damage and decreased AChE activity in the mice. This suggests that zeatin might be useful for protecting cognitive dysfunction, as well as for reducing the activation of AChE in dementia.