Abstract: Objective To investigate the characteristics of gray scale ultrasonography and blood flow in benign and malignant breast tumors by high frequency color Doppler ultrasound. Methods A retrospective analysis was made on 60 patients with breast tumors who underwent high frequency color Doppler ultrasonography from November 2016 to May 2018. According to the results of pathological examination, they were divided into malignant group (30 cases) and benign group (30 cases). In order to explore the value of high frequency color Doppler ultrasonography in the differential diagnosis of breast tumors, the gray scale ultrasonographic features of breast tumors (tumor shape, boundary, gravel calcification, longitudinal/transverse ratio, posterior echo) and blood flow grading and spectrum characteristics were compared and analyzed. Results ①Compared with benign group, the following gray scale ultrasonographic features of malignant group were more significant showing irregular shape of tumors (25/30 vs. 3/30), burr-like or crab-foot-like changes at the edge (23/30 vs. 5/30), gravel-like changes (16/30 vs. 4/30), longitudinal/transverse ratio >1(13/30 vs. 1/30), posterior echo attenuation (11/30 vs. 2/30),and the differences were statistically significant (all P<0.05); ②Compared with the benign group, the following blood flow characteristics of malignant group were more significant indicating blood flow distribution II, III (26/30 vs. 4/30), hemorrhagic flow spectrum (27/30 vs. 10/30), peak flow velocity≥20 cm/s (18/30 vs. 2/30), resistance index≥0.7 (25/30 vs. 2/30). The above differences were statistically significant (all P<0.05). Conclusion High-frequency color Doppler ultrasound has distinct manifestations in the gray scale and blood flow characteristics of benign and malignant breast tumors, and has high value in differential diagnosis.