Abstract： Objective To investigate the abnormality of parameters of thyroid function and incidence of autoimmune diseases in children with vitiligo.Methods A total of 363 children with vitiligo,including 198 males and 165 females were recruited into this study together with 93 normal human controls(55 males and 38 females).The serum levels of free tetraiodothyronine,free triiodothyronine,thyroid stimulating hormone,antithyroperoxidase antibody and thyroglobulin antibody were determined by chemiluminescent immunoassay in these subiects.Results The abnormality of parameters of thyroid function was observed in 43 out of 363(11.8%)patients affected by vitiligo and in 4 out of 93(4.3%)normal human controls;a significant difference was observed between the two groups (P＜0.05).Of the 43 patients wim abnormality of parameters of thyroid function,39 were diagnosed as vitiligo vulgaris,4 as segmental vitiligo.A significant increase Was observed in the incidence of abnormality of parameters of thyroid function in patients with vitiligo vulgaris compared with those with segmental vitiligo(P＜0.05).Conclusion There is an increase in tbe abnormality of parameters of thyroid function in children with vitiligo.