Alzheimer disease（ AD） is one of the most common neurodegenerative diseases， which often has an insidious onset and is lack of effective treatments. Mild cognitive impairment（ MCI）， which partly can develop into AD， is a state of cognitive impairment between normal aging and dementia. The major core clinical symptoms of AD include memory impairment， cognitive dysfunction， changes of personality and behavior. Many studies have shown that AD may be accompanied by sensory disturbances， such as smell， vision， hearing， etc.， among which olfactory disturbances may be one of the early clinical symptoms of MCI or AD， and MCI and AD patients may have sensation-related electrophysiological changes. This article reviews the progress of sensory disturbance and related electrophysiological change in MCI and AD patients.