Objective To observe the clinical effect of Xiehuo Xiaoying Decoction in treating Toxic diffuse goiter（ called Graves disease） with hyperactivity of heart-liver fire syndrome. Methods Eighty patients with Graves disease were randomized into a treatment group（ 40 cases） and a control group（ 40 cases）. Both groups were given thiamazole tablets. The treatment group was added with Xiehuo Xiaoying Decoction one dose every day. There were 4weeks as a course

and both groups were treated for 3 courses. Heart rate

body weight

and Chinese medicine syndrome score of patients in both groups were compared before and after treatment. Thyroid function [including thyroidstimulating hormone（ TSH）

free triiodothyronine（ FT3） and free thyroxine（ FT4） ]were tested before treatment and during the 1st

2nd and 3rd courses. Indexes recovery rates and average time of recovering to normal level were calculated. Level of thyrotrophin receptor antibody（ TRAb） was detected before and after treatment. Thiamazole tablets dosage was recorded in the 3 courses. Results Finally

61 patients

including 30 cases in the treatment group and31 cases in the control group

completed the study. As for slowing heart rate and reducing Chinese medicine syndrome score

the treatment group was superior to the control group（ P < 0. 05 or P < 0. 01）. Compared with those in the control group

the levels of FT3 and FT4 in the treatment group at the 1st and 2nd course were lower. The time for FT3 and FT4 recovering to normal

as well as the recovery rate at the 1st course in the treatment group was superior to those in the control group（ P < 0. 05 or P < 0. 01）. Thiamazole tablets dosage in the treatment group at the 1st

2nd and 3rd course were lower than those in the control group at the same time point（ P < 0. 05 or P < 0. 01）. After treatment

patients in both groups gained weight

and their level of TSH increased and the level of TRAb decreased（ P <0. 01）. There was no significant difference in indexes between the two groups after treatment（ P > 0. 05）. Conclusion Xiehuo Xiaoying Decoction might reduce the dosage of Western medicine in treating Graves disease

and it might relieve the clinical symptoms and improve thyroid function quickly.