Abstract: Objective To study the effect of Coeloglossum viride var. bracteatum extract (CE) on the learning and memory ability in dementia rats by ibotenic acid (IBO), and explore its mechanism. Methods IBO (2 μl, 8 g/L) was stereoscopic injected into unilateral nbM of SD rats to produce AD-mimic animal model. CE was given to rat by intragastric administration (5mg/kg) 1h before the stereoscopic operation, and after the operation once a day. The Morris water maze test and the step down test was taken. The expressions of acetylcholinesterase (AChE), choline acetyltransferase (ChAT), nerve growth factor (NGF) and tyrosine kinase (TrkA) in the hippocampus, cortex and striatum were examined by Western blot. Results CE significantly improved the learning and memory ability in IBO-induced AD-mimic rats. CE treatment shortened escape latency significantly as compared with nbM-lesion rats. The expression of AChE increased significantly in nbM-lesion rat hippocampus; CE inhibited the excessive expression of AChE. Conclusion CE could improve the dysfunction of learning and memory ability in AD animals by inhibiting the excessive expression of AChE in hippocampus under the pathological condition.