It has long been recognized that hepatic steatosis (fatty liver) occurs in obese children as in adults. Steatosis of any etiology can be associated with the development of necro-inflammation and fibrosis, so called steatohepatitis, and even cirrhosis. Nonalcoholic steatohepatitis (NASH) has been proposed as a component of insulin resistant syndrome and exists in pediatric population. The other etiology of NASH in children has not been clearly understood. In addition to obesity, adipose tissue distribution also appears to influence metabolic complications. Subjects with visceral fat adiposity appear to be at risk for fatty liver because of their ability to transport free fatty acids directly into the portal vein for conversion to triglycerides within the liver. A stronger relationship of serum ALT to visceral adiposity than BMI was demonstrated. Many metabolic diseases such as Wilson's disease, NICCD, OTC deficiency, carnitine deficiency have steatohepatitis and cirrhosis. It may play the important role to reveal the mechanism of progress to NASH.