Alzheimer disease（ AD） is the most common type of dementia， and its pathogenesis is complex and has not been completely clear to date. Studies have shown that a large number of abnormalities in the structure and function of brain microvasculature are associated with AD lesions， suggesting that the changes of brain microvasculature may be involved in the occurrence and development of AD. This article reviews the microvascular changes of AD and its effect on the treatment.