The Klotho gene is an anti-aging gene， and the Klotho encoded protein has the effect of antiaging and prolonging lifespan， which is closely related to cognitive function. Klotho protein plays an important role in cognitive impairment of neurodegenerative diseases such as Alzheimer disease， Parkinson disease， and frontotemporal dementia， and vascular cognitive impairment. It can protect cognitive function by such means as mitigation β-amyloid protein burden， reduce inflammatory reaction， resist oxidative stress and other ways. This paper summarizes the current research progress on Klotho gene， Klotho protein and various types of cognitive impairment at home and abroad， in order to provide a theoretical basis for the research in this field.