Abstract: Objective: To discuss the correlation between ultrasonic characteristics of thyroid nodules and Chinese medicine syndrome differentiation typing. Methods: Patients who were examined by the thyroid ultrasonography and diagnosed with thyroid nodules were enrolled, and their Chinese medicine syndrome types were determined. Information related to thyroid nodules such as the number, the maximum diameter and the average diameter of larger nodules, the composition,echo pattern,homogeneity of internal echo,morphology,margin,calcification and blood flow signals were recorded through ultrasonography,and the above information was classified based on ACR TI-RADS. The differences of each ultrasonic characteristic of thyroid nodules in different Chinese medicine syndrome types were counted and analyzed. Results:Among enrolled 311 eligible cases,there were 148 cases with phlegm retention and blood stasis syndrome,93 cases with phlegm-dampness accumulation syndrome,and 70 cases with qi constraint and phlegm obstruction syndrome. There was significant difference being found in the comparison of margin,morphology named aspect ratio and calcification of thyroid nodules in the three groups with different syndromes(P<0.05);there was lobulated or irregular thyroid nodules,the aspect ratio more than one and calcification in the group with qi constraint and phlegm obstruction syndrome,accounting for 24.3%,27.1% and 37.1% respectively,and the detection rate of the three ultrasonic characteristics was higher than that in the other two groups(P<0.05). There was no significant difference being found in the comparison of the number of thyroid nodules, the maximum diameter of larger nodules, the average diameter and the composition of nodules, echo pattern, homogeneity of echo and blood flow signals in the three groups with different syndromes(P>0.05). There was significant difference being found in the comparison of ACR TI- RADS classification of nodules in the three groups with different syndromes(P<0.05). When compared ACR TI-RADS classification of thyroid nodules among the groups with qi constraint and phlegm obstruction syndrome, phlegm retention and blood stasis syndrome and phlegm- dampness accumulation syndrome,the difference among the groups was significant(P<0.05);ACR TI-TADS classification centered on TR4 and TR5 in the group with qi constraint and phlegm obstruction syndrome,and TR3 and TR4 were the centers of classification in the groups with phlegm retention and blood stasis syndrome and phlegm- dampness accumulation syndrome. There was no significant difference being found in the comparison of ACR TI-TADS classification between the groups with phlegm retention and blood stasis syndrome and phlegm- dampness accumulation syndrome(P>0.05). Conclusion: There is certain correlation between ultrasonic characteristics of thyroid nodules and Chinese medicine syndrome types. In the group with qi constraint and phlegm obstruction syndrome, lobulated or irregular thyroid nodules, the aspect ratio more than one and visible calcification are more common,and the score of ACR TI-RADS classification is higher.