Alzheimer's disease(AD) is one kind of neurodegenerative diseases,also the main reason leading to dementia.tau protein is a microtubule-associated protein,and its hyperphosphorylation plays a key role in the pathogenesis of AD.In this review,we made a summary of latest research progresses on the neurotoxicity of tau protein hyperphosphorylation and the relationship between tau protein hyperphosphorylation and AD.