Abstract: Objective　To compare and analyze the clinical and ultrasonographic characteristics of breast radial scar (RS) and breast cancer. Methods　From February 2015 to December 2017, 40 patients with RS and 40 patients with invasive ductal carcinoma (IDC) confirmed by the Department of Pathology of Tianjin Medical University Cancer Hospital and examined by breast ultrasound were selected. The baseline data were collected in the 2 groups of patients including age, menstrual status, history of lactation, history of abortion, lesion side, history of ipsilateral breast surgery and clinical symptoms. Results of preoperative breast ultrasound examination, ultrasound images (morphology, margin, internal echo, posterior echo, peripheral hyperecho halo, calcification), blood flow signal and elasticity score were also collected. The changes in clinical and ultrasonic characteristics were compared between the two groups. With pathological diagnosis as the gold standard, receiver operating characteristic curve (ROC) was used to evaluate the diagnostic efficacy of color doppler ultrasound combined with elastography. Results　Both the RS and IDC groups were mostly breast masses. Compared with the IDC group, the RS group showed regular shape, well-defined margins, no peripheral hyperechoic halo, homogeneous internal echogenicity, no calcification, no blood flow signal, no alteration/enhancement of posterior echogenicity and benign elasticity score (P＜0.05). The ROC curve indicated that the combined prediction of RS and IDC by two-dimensional ultrasound BI-RADS, color blood flow signal and elasticity score had a good diagnostic efficiency. The area under the curve (AUC) was 0.802 (95%CI: 0.673-0.930, P＜0.05), the sensitivity was 0.833, and the specificity was 0.652. Conclusion　The ultrasonic characteristics of the RS group and the IDC group are different. Color doppler ultrasonography combined with elastography is of great significance for the differential diagnosis of the two lesions.