Abstract: Objective To explore the value of real-time shear wave elastography (SWE) in diagnosis of thyroid micro carcinoma (TMC). Methods Out-patients with thyroid small nodule suspected malignant who underwent ultrasound examination from June 2014 to December 2014 in our hospital were enrolled in this study. Sixty-seven nodules (≤1.0 cm) in 62 patients were examined by SWE to get the Young's modulus. Pathologic results were served as the golden standard to construct the ROC curves, and the value of SWE in diagnosis of TMC was evaluated. Results Of the 67 nodules, 37 were TMC and 30 were benign. The maximum and mean elasticity value of TMC were (58.47±31.51) kPa and (41.58±23.36) kPa, while the maximum and mean elasticity value of the micro benign nodules were (26.94±14.31) kPa and (18.03±10.83) kPa, which were signifcantly lower than those of TMC (t= 5.063, P = 0.000; t= 4.591, P=0.000); Taking 40 kPa as the threshold of the maximum elasticity value, the sensitivity was 84.3% and the specifcity was 91.2%. Taking 35 kPa as the threshold of the mean elasticity value, the sensitivity was 80.0% and the specifcity was 94.2%. The area under the ROC curve of the maximum, mean elasticity value was 0.942, 0.923 (P＜ 0.05). Conclusion SWE can be used for the quantitative determination of thyroid micro carcinoma hardness, and it is helpful in differential diagnosis of thyroid micro carcinoma.