Objective：To evaluate the clinical value of SWE in predicting ipsilateral axillary sentinel lymph node metastasis in breast cancer. Methods A total of 70 patients with breast cancer confirmed by pathology were enrolled in the Affiliated Hospital of North Sichuan Medical College. Percutaneous sentinel lymph node contrast-enhanced ultrasound （SLN-CEUS） was performed on the affected side，and the locations of drainage lymphatic vessels and lymph nodes were marked on the body surface。SWE was used to evaluate the lymph node

recording the type of ultrasonic image and elastic modulus（Emax、Emin、Emean、SD）。The ultrasonographic features of metastatic lymph nodes were analyzed based on the pathological results. Results: Emax，Emean and SD of metastatic lymph nodes were higher than those of non-metastatic lymph nodes （P < 0.05）.The cut-off value of ROC in SWE classification suggested that SLN with“Rim of stiffness”，“Colored lesion”，“Defect filling”（Type II

III

IV ）were at high risk of becoming metastatic SLN. It was of high clinical value to determine the nature of lymph nodes by qualitative classification of SWE

the Kappa value

AUC，sensitivity，specificity，PPV and NPV were 0.798，0.902，81.8%，97.3%，96.4%and85.7%

respectively.Conclusion: SWE had specific manifestations in metastatic SLN which can help to identify the nature of SLN.SWE was real-time，convenient and non-invasive. It can improve the detection of SLN metastasis effectively.