Objective To explore effects of simple obesity on children's constitution and health status,provide theoretical basis for the prevention and early intervention in simple obesity. Methods Combined with requirements of "national student physical health standard" of the Ministry of Education and State Sports General Administration,according to Achenbach's Child Behavior Checklist(CBCL),constitution and health status of 103 cases simple obesity children and 102 cases normal children were comparative analysed. Results 1) The body shape indexes included body mass index,chest circumference,skinfold thickness in obese children were significantly higher than those in proportion group.2) Vital capacity body mass index of physiological in obesity group was lower than those in proportion group.3) In the physical quality target,standing long jump,solid ball,sit-and-reach and grip strength index of obesity group were lower than those in proportion group.Obesity group spent more time than proportion group on 25 m×2 shuttle run.4) Psychological quality and social adaptation ability of obesity group were lower than those of proportion group.5) Comprehensive evaluation of physique health indexes,the excellent and good rate and compliance rate of obesity group were 11.7% and 67.0%,proportion group were 59.8% and 91.2%. Conclusion Simple obesity significantly affects children physical shape,physiological function,physical,psychological quality and social adaptation ability,and it is harmful to the healthy growth of children,so medical and educational worker should pay close attention to it.