The greater prevalence of fatty liver in China is more often associated with obesity than with alcohol abuse. The prevalence of non-alcoholic fatty liver disease in the general adult population is as high as 15% in the more affluent areas of China. With increasing obesity, the prevalence of nonalcoholic fatty liver has increased exponentially in the last decade. Various tissue types of NAFLD exist in our patients, but to date, the severity of liver lesions is usually mild and often easily overlooked by those with the disease. However, patients with NAFLD have an increased prevalence of metabolic disorders, diabetes mellitus and cardiovascular disease. Therefore, public health interventions are needed to slow down the national epidemic of obesity in order to improve the effective prevention and treatment of liver as well as metabolic complications in patients with fatty liver. Nonalcoholic fatty liver disease is an acquired metabolic stress-related liver disease, and the disease spectrum of nonalcoholic fatty liver includes simple fatty liver, nonalcoholic steatohepatitis and its associated cirrhosis, and hepatocellular carcinoma. Nonalcoholic fatty liver disease tends to present with mild symptoms, which may include signs and symptoms such as malaise, dyspepsia, vague pain in the liver area, overweight and/or visceral obesity, and hepatosplenomegaly. Non-alcoholic fatty liver disease does have mildly elevated laboratory tests for transaminases (ALT, AST), elevated serum cholinesterase, elevated lipids (mainly triglyceride TG), and elevated fasting glucose. Special attention should be paid to chronic hepatitis B and chronic hepatitis C combined with nonalcoholic steatohepatitis, and timely antiviral therapy if antiviral pointers are available. The importance of lifestyle changes and weight loss in the management of liver disease and diabetes mellitus and atherosclerosis must be emphasized in nonalcoholic fatty liver disease. In view of the great danger of insulin resistance and nonalcoholic fatty liver disease to human health, it is recommended that the whole society should maintain a healthy lifestyle, reduce dietary fat and calorie intake, and increase physical activity.