The present invention relates to a composition for preventing or treating neurological diseases including an extract of Euphoria longan fruit, red sage and Gastrodia elata as an active ingredient. The composition of the present disclosure has a superior effect of inhibiting the activity of acetylcholinesterase (AChE), which hydrolyzes the neurotransmitter acetylcholine directly involved in impairment of cognitive function. In addition, the composition of the present disclosure is safe for the human body since the biologically safe extract of Euphoria longan fruit, red sage and Gastrodia elata is used as the active ingredient.