Abstract: To explore the changes of thyroid hormones in children with simple obesity，and to provide theoretical basis for the treatment of simple obesity and improving the quality of life of obese children. Child obesity is closely related to changes in thyroid function. Obese children have higher levels of thyroid-stimulatinghormone(TSH) than ordinary children. The currently accepted hypothesis shows that its mechanism is related to leptin. A mild increase in TSH is more like an adaptive change in body weight， rather than a cause of obesity. Selective thyroid hormone receptor agonist may become a potential drug for the treatment of obesity in the future. It remains to be verified by more clinical studies whether it can be used in the treatment of childhood obesity.

Key words: Simple obesity, Thyroid function, Leptin, Child