Objective To establish the reference intervals for thyroid-stimulating hormone(TSH) ,triiodothyronine(T3 ) ,thy-roxine(T4 ) ,free triiodothyronine(FT3 ) and free thyroxine(FT4 ) in healthy people aged between 18 and 60 years old in Haikou are-a .Methods According to the recommendations of clinical and laboratory standards institute(CLSI)C28-A3 document ,401 persons aged between 18 and 60 years old were recruited from Haikou(275 male ,126 female) .The makers were analyzed by gender .Estab-lished the reference intervals of TSH ,T3 ,T4 ,FT3 and FT4 in Haikou area .Results Reference intervals based on gender were estab-lished as TSH(0 .58-4 .60 mIU/L) ,T3 (1 .11-2 .31 nmol/L for male ,0 .97-2 .13 nmol/L for female) ,T4 (72 .24-152 .22 nmol/L ) ,FT3 (4 .17-6 .33 pmol/L for male ,3 .95-5 .47 pmol/L for female) ,FT4 (13 .16-21 .29 pmol/L for male ,12 .13-19 .61 pmol/L for female) .Conclusion This study has established the reference intervals of TSH ,T3 ,T4 ,FT3 and FT4 in healthy people aged between 18 and 60 years old in Haikou area .