Abstract: Alzheimer′s disease (AD) is the most common degenerative disease of the central nervous system. To date, there is no effective treatment for AD and it is difficult to prevent the disease in the early stage. Increasing studies focus on total cholesterol (TC) as a modifiable factor in AD prevention. Epidemiological studies revealed that midlife high TC level is one of risk factors for AD development and changes in TC trajectory are also associated with AD development. Clinical studies also explored the relationship between the use of cholesterol-lowering drugs and AD. In addition, fundamental researches indicate that cholesterol homeostasis and cholesterol-related genes play an important role in the pathogenesis of AD. These studies provide insights into the pathogenesis and early prevention of AD. The study reviews current researches on the relationship between cholesterol and AD and discusses research prospects.