Abstract: Objective To retrospectively analyze the changes of sonogram before and after neoadjuvant chemotherapy（NAC） for estrogen receptor（ER） negative breast cancer, and to explore the value of ultrasound in evaluating the efficacy of NAC in early, middle and late stages. Methods 89 patients with ER negative surface type（48 cases with HER-2 overexpression type and 41 cases with basal-like type）were subjected to dynamic ultrasonic monitoring before and after NAC, and were divided into major histological response group and non-major histological response group according to the postoperative pathological results, retrospectively analyzed the changes of sonogram before NAC and NAC in early,middle and late stages. Results The total NAC response rates of patients with HER-2 over expression type and basal-like type were 75.0% and 53.66%, respectively, with significant differences （P<0.05）. In the HER-2 overexpression type, the reduction rate of maximum diameter,internal blood flow were statistically significant differences in the early, middle and late stages of NAC （all P<0.05） and two-dimensional image characteristics change in the early stage of NAC （P<0.05）. In the basal-like type, the reduction rate of maximum diameter was statistically significant differences in the early and middle stages of NAC （all P<0.05）, internal blood flow in the middle and late stages （all P<0.05） and two-dimensional image characteristics change in the early stage （P<0.05）. Real-time tissue elastography score before and after the change in the NAC was not statistical difference （P>0.05）. Conclusions Ultrasound can accurately evaluate the efficacy of ER negative breast cancer after NAC by dynamically observing the changes of the maximum diameter of the lesion, internal blood flow, two-dimensional image characteristics, before and after NAC. The changes of indicators of efficacy evaluation of HER-2 overexpression type and basal-like type were not consistent, so the accuracy of evaluation could be further improved by combining the consideration of molecular typing of breast cancer in ultrasonic evaluation.