Objective To observe the clinical effect of Shugan Qingre Fang（ 疏肝清热方） in the treatment of Hashimoto thyroiditis（ HT） and to explore the possible mechanism. Methods Eighty HT patients were randomized into the treatment group（ 40 cases） and the control group（ 40 cases）. Another healthy control group（ 20 cases） was established. The treatment group was given herb compound prescription granules of Shugan Qingre Fang

one dose daily. The control group was given 25μg of levothyroxine sodium tablets once daily. Both groups took medicine orally for 12 weeks. The healthy control group was not given any medicine. Thyroid function

thyroid antibody and scores of Chinese medicine syndromes in two patient groups were observed before and after treatment. Therapeutic effect was evaluated in two patient groups after treatment. Level of peripheral lymphocyte factor was tested in three groups before treatment. Results Total effective rate was 85. 00% in the treatment group

and 62. 50% in the control group

with a significant difference between the two groups（ P < 0. 05）. There was no significant difference in thyroid function in the treatment group before and after treatment（ P > 0. 05）. After treatment

levels of thyroid peroxidase antibody（ TPO-Ab） and thyroglobulin antibody（ Tg-Ab） decreased remarkably in the treatment group（ P < 0. 01）; but there was no significant difference in level of thyrotropin receptor antibody（ TR-Ab） in the treatment between before and after treatment（ P > 0. 05）. After treatment

scores of Chinese medicine syndromes decreased significantly in the treatment group（ P < 0. 01） and it was obviously lower than those in the control group after treatment（ P < 0. 05）.The expressions of CCR5% and CD30% of HT patients in both groups were higher than those in the healthy control group before treatment; while CCR5 / CD30 in both groups was lower than that in the healthy control group（ P <0. 01）. Conclusion Shugan Qingre Fang could improve antibody levels and clinical symptoms of HT patients.The mechanism might relate to improving balance shift of helper T cell.