Abstract: CLINICAL APPLICATION OF sTSH IRMA AND FT_3，FT_4 RIA FOR THYROID FUNCTION DIAGNOSES ON THE THYROID DISEASES AND NONTHYROID ILLNESSES Chen Rendu Ji Huizhi Han Xiuqing Guo Suping Zhang Wei（Nuclear Medicine Deoartment of the First Teaching Hospital in shanxi Medical Couege，Taiyuan 030001）ABSTRACT sTSH（IRMA）and FT_3，FT_4（RIA）kits which were made in China Institute of Atomic Energy areused tO measure serum TSH，FT_3 ，FT_4 concentrations in171 normal subjects.The mean values are2．57±1．16 mIU／1，3．76±1．53 pmol／l and l 7．1±4．4 l pmol／l respectively.61 hyperthyroid and55 hypothyroid patients are measured ，too. Their mean values of TSH，FT_3 and FT_4 are 0.25±0.09mIU/1，16.41±5.08 pmol/1.49. 57±14.93 pmol／1；17．24 ± l3．82 mIU／1，1.12l± 0．48pmol／1，5.04土2. 45 pmol／l respectively. Furthermore，sTSH，FT_3 and FT_4 are detected and dis-cussed in the 44 nonthyroid ilInesses（NTI）．All of TT_3 mean values for NTI are less than those of nor－mal subjects，so this kind of diseases is named low T_3 syndrome.The study deems that sTSH，FT_3 andFT_4 tests are very important and valuable in the diagnosis and differential diagnosis Of thyroid diseasesand NTI.Key Words M-TSH M-FT_3 M-FT_4 low T_3 syndrome