Purpose: With remarkable increase in the prevalence of childhood obesity, nonalcoholic fatty liver disease increased, The aim of this study is to evaluate the prevalence of the increase liver enzymes, lipid levels and fasting blood glucose level in normal and obese children. Methods: A total of 2206 elementary students were grouped according to obesity index; normal group and obesity group(mild, moderate, severe). Aspartate aminotransferase(AST, SGOT) and alanine aminotrausferase(ALT, SGPT) were measured with tota1 cholesterol, triglyceride and fasting blood glucose. Results: Compared with the 2.7% of ALT > 50 IU/L in normal group, obese groups showed significantly higher prevalence; 6.7% in mild obesity group, 11.8% in moderate group and 15.0% in severe group. The prevalence of hypertriglyceremia was 12,4% in normal weight group, which is significantly lower than obesity group(mild obesity group 24.8%, moderate and severe 32.1% each). Conclusion: The prevalence of nonalcoholic fatty liver increased along with severity of obesity. Of Nutritional assessment, intervention, and preferably prevention are necessary for health promotion elementary students.