Abstract:Objective] To explore the change of serum triiodothyronine(T3 ) ,thyroxine(T4 ) ,thyroid stimulating hormone(TSH) ,free T3(FT3 ) and free T4(FT4 ) in children with hand foot mouth disease(HFMD) .[Methods]A total of 81 children with HFMD infected by enterovirus 71(EV71) in feces detected by RT‐PCR were divided into common type group( n=22) ,severe type group( n=19) and critically severe type group( n=40) .Serum levels of thyroid hormones T3 ,T4 ,FT3 ,FT4 and TSH of 3 groups were detected by chemiluminescence method .[Results]There was no significant difference in serum levels of T3 ,T4 ,FT4 ,FT3 and TSH among 3 groups( P>0 .05) .[Conclusion]Serum levels of thy‐roid hormones in children with HFMD infected by EV71 is not associated with the severity of disease .