Objective : As obesity has been increasing in China, the present study examined the body composition of children to assess their fatness. Study design : A total of 532 healthy schoolchildren who lived in central Beijing were examined. Skinfold thicknesses, hip and waist circumferences, and body fat percentage were measured, as well as height and weight. Results : The prevalence of overweight (Body Mass Index (BMI) greater than or equal to 95% for age and sex of Chinese children) was 27.7% in boys and 14.2% in girls (chi-squared; P = 0.0001). The percentages of body fat (BF%), waist/hip ratios and skinfold thicknesses ratios (subscapular/triceps) in overweight children were significantly higher than those in non-overweight children (Mann-Whitney U -test). The BF% of non-overweight boys was significantly higher than that of non-overweight girls. Conclusion : Urban Chinese overweight children have high BF% with adverse fat distribution. They may have high risk of atherogeniety. Boys in the non-overweight category may have higher fat accumulation than predicted by BMI. The establishment of an intervention program for childhood obesity is strongly recommended.