Mild cognitive impairment (MCI) refers to a group of individuals who have some cognitive impairment but of insufficient severity to constitute dementia1,which is a transitional stage between normal aging and dementia. Amnestic MCI is the most common subtype of MCI, which shows the least reversion to normal, and is defined as a significant impairment in memory but with no impairment in activities of daily living. In an interventional study of patients meeting Petersen criteria for amnestic MCI, 16% progressed to dementia per year, 99% of whom received an AD diagnosis. Hence, MCI, in particular amnestic MCI is generally recognized in many cases to represent prodromal AD and becomes a new target for prevention and treatment of AD.