Background Synapses are highly motile and can undergo remodeling even in the adult nervous system．Synapse remodeling and the formation of new synapses are activity-dependent processes that provide a basis for memory formation．There is growing evidence that mild cognitive impairment in early AD (Alzheimer’s disease) may be due to synaptic dysfunction.Objective To review the roles of synaptic dysfunction in Alzheimer’s Disease. Content Recent work suggests that loss of synapses is a evident histoneurological change in the early stages of cognitive deficiency in AD. The extent of snaptic loss has been found to be an excellent correlate of the degree of dementia, so it has been shown to be the best pathologic correlate of cognitive decline.Trend Further research into this area may provide useful insights and directions into the early intervention and treatment of Alzheimer’s disease.