Objective：To discuss the correlation between ultrasonic characteristics and Chinese medicine syndromes in patients with sub-acute thyroiditis.Methods：A total of 65 patients with sub-acute thyroiditis diagnosed by thyroid biopsy were included in the study，and were examined by Chinese medicine syndrome differentiation and ultrasound(ultrasound elastography).The ultrasonic manifestations of patients with different Chinese medicine syndromes were observed and the ultrasonic examination images of them were graded and at last the Chinese medicine syndromes of patients at different grades of ultrasound were compared.Results：The Chinese medicine syndrome were mainly the syndrome of wind-heat and phlegm coagulation；there was significant difference in the comparison between the syndrome of wind-heat and phlegm coagulation and the syndrome of liver depression and qi deficiency(χ2=4.680，P=0.031).There was significant difference in the comparison between the syndrome of wind-heat and phlegm coagulation and the syndrome of deficiency of both qi and yin combined with phlegm coagulation(χ2=8.613， P=0.003).The main ultrasonic manifestations of the patients included goiter，lamellar hypoechoic area，abundant blood flow signals around the hypoechoic area，and the peak flow rate of the superior thyroid artery over 40 cm/s.There was significant difference in the comparison of each ultrasonic manifestation between patients with the syndrome of wind-heat and phlegm coagulation and those with syndrome of deficiency of both qi and yin combined with phlegm coagulation(P＜0.05).There was significant difference in the comparison of goiter and lamellar hypoechoic area between patients with the syndrome of wind-heat and phlegm coagulation and those with syndrome of liver depression and qi deficiency(P＜0.05).There was significant difference in the comparison of each ultrasonic manifestation(except for goiter)between patients with the syndrome of wind-heat and phlegm coagulation and those with syndrome of deficiency of both qi and yin combined with phlegm coagulation(P＜0.05).There was significant difference in the comparison between proportion of ultrasound elastography of grade and the grade 0(χ2=15.577， P=0.000).There was significant difference in the comparison between proportion of grade and the grade (χ2=5.969，P=0.015).There was no significant difference in the comparison between proportion of grade and the grade (χ2=1.851，P=0.174).There was no significant difference in the comparison between proportion of grade and the grade (χ2=2.459，P=0.117).In terms of the comparison of the distribution of Chinese medicine syndromes with different ultrasound elastography grades，at grade 0，there was significant difference between syndrome of wind-heat and phlegm coagulation and syndrome of liver depression and qi deficiency(χ2=4.800，P=0.028)；at grade ，there was significant difference between syndrome of wind-heat and phlegm coagulation and syndrome of liver depression and qi deficiency as well as syndrome of deficiency of both qi and yin combined with phlegm coagulation(χ2=7.765， 6.017， P=0.005， 0.014)； at grade ， there was significant difference between syndrome of wind-heat and phlegm coagulation and syndrome of liver depression and qi deficiency as well as syndrome of deficiency of both qi and yin combined with phlegm coagulation(χ2=7.337，5.250，P=0.007，0.022).Pairwise comparison of other syndrome types showed no statistical significance(P＞0.05).Conclusion：The ultrasonic characteristics are closely related to Chinese medicine syndromes in patients with sub-acute thyroiditis.The ultrasonic manifestations of patients with different Chinese medicine syndromes are significantly different，and the distribution of Chinese medicine syndromes of patients with different ultrasound elastography grades is also significantly different，while the ultrasound elastography grading is higher.