Objective: The purpose of this study was to observe the efficacy of Chaihu Shugan San(CHSGS) in the treatment of subacute thyroiditis in plateau area. Method: In this study

one hundred and sixteen cases of patients were included and randomly divided into the traditional Chinese medicine (TCM) group and the western medicine group by odd and even numbers

with 58 cases in each group. The patients in the Western medicine group were treated with conventional western medicine

and the patients in the TCM group were given CHSGS on the basis of conventional western medicine. The efficacy was observed after treatment

and the recurrence were observed in the following six months. Result: After one month

the total efficiency in the TCM group was 96.55%

while it was 81.03% in the western medicine group

and the difference was statistically significant (P<0.05). The FT3

FT4

C-reactive protein(CRP)

ESR in the TCM group decreased significantly

and thyroid stimulating hormone(TSH) was increased and the difference was statistically significant compared with the Western medicine group(P<0.05). In the TCM group

there were 5 recurrence cases after six months

and the recurrence rate was 8.62%

while in the western medicine group there were 26 recurrence cases with a recurrence rate of 44.83%

the difference between two groups was statistically significant (P<0.05).There was no adverse reaction in both two groups. Conclusion: CHSGS combined with the western medicine was curative in the treatment of subacute thyroiditis

which can significantly reduce the relapse rate

and be worth of promoting in clinical.