Acethylcholinesterase (AChE) inhibitors have been used in the treatment of Alzheimer’s disease (AD). Currently, the only effective treatment for AD disease targets the cholinergic system using anti-cholinesterase compounds. AD is progressive, degenerative disease characterized by memory loss, language deterioration, poor judgment, impaired visuospatial skills etc. There are a few synthetic medicines, e.g. tacrine, donepezil and the natural product-based rivastigmine and galantamine to treat cognitive dysfunction and memory loss associated with AD. These approved drugs are limited in use due to their adverse side effects such as gastrointestinal disturbance and bioavailability problems. There still is great interest in fi nding better AchE inhibitors. We have screened in this study the anti-acethylcholinesterase effects of 87 samples, which prepared from different parts of 43 plant species. Methanolic extracts of nine plants, namely Patrinia rupestris, Numpaea candida, Lespedeza hedysaroides, Pachypfeurum alpinum, Leontopodium Leontopodioides, Nonea pulla, Leontopodium compestre, Gypsophilea patrinii and Abies sibirica showed potent effect, their inhibition ratios were 39.65%, 42.22%, 38.06%, 40.55%, 38.82%, 35.1%, 35.85%, 35.3 % and 53.01%, respectively. Our research shows that some Mongolian medicinal plants have anti-acetylcholinesterase activity, furthermore investigations needed to isolate pure bio-active compounds from these active plants and determine their chemical structures.