Objective:To investigate the behavior problems commonly found in simple obesity children. Methods: One hundred obesity children (experimental group) and 100 normal children (control group) were recruited. The Achenbach Child Behavior Checklist was used to assess the behavior problem and social adaptive ability of children. Results: Obese boys showed higher frequency in displaying aggressive behavior, violating discipline, having hyper-kinetic and compulsive behavior, while obese girls had higher scores on poor social skills, depression, immaturity and anxious behavior problems. Conclusion: Children having simple obesity had more behavior problems than non-obese children. Early intervention with an integrated approach involving family, school and community is necessary for preventing behavior and emotional disorders of obese children and improving their mental health condition.