Alzheimer's disease (AD) is the most common type of dementias and becoming a worldwide problem. As the time goes by, more and more researches show that AD is related to cholesterol in the brain. Both the Aβ and the phosphorylated tau are believed to be the key factors in the pathogenesis of AD. Cholesterol in the brain is involved in a series of interdependent metabolism processes of Aβ including the synthesis, aggregation, neurotoxicity, and elimination. The phosphorylated tau is also considered to be related to cholesterol metabolism. Besides that, there is evidence suggesting that cholesterol might contribute to the pathogenesis of AD by inducing the dysfunction of cerebral vessels such as the arteriosclerosis and cerebral amyloid angiopathy (CAA). In this review, we summarize our current understanding on the role of cholesterol in the pathogenesis of AD, and also propose the therapeutic research process on cholesterol-regulating drugs in the treatment of AD pathology.