Abstract: Nonalcoholic fatty liver disease (NAFLD), a metabolic stress-induced liver disease, is closely related to genetic susceptibility and insulin resistance (IR). It represents hepatic manifestation of metabolic syndrome (MS), and is associated with obesity, type 2 diabetes, hypertension, dyslipidemia, and metabolic syndrome. The prevalence of NAFLD increased year by year, and it is higher in the patients with type 2 diabetes and obesity. Atherosclerosis (AS) is the basic of cardiovascular disease (CVD), it is found that NAFLD was closely associated with CVD, and NAFLD was the cause of death in patients with CVD and malignant tumor. Also, there is a closely relationship between NAFLD and AS. The mechanism is not clear, and it may be related to insulin resistance, atherogenic dyslipidemia, oxidative stress, inflammation, the changes of fat hormone level and function in liver cell, etc. In this article, the relationship and possible mechanism between NAFLD and AS were reviewed.