Objective: To investigate the impact of the change of Ki-67 expression after neoadjuvant chemotherapy (NCT) on prognosis of breast cancer and its relation with the breast cancer molecular subtypes. Methods: The clinical data of 121 patients with stage IIA-IIIC breast cancer undergoing NCT from 2010 to 2013 were reviewed. The relationship between the change of Ki-67 expression after NCT and prognosis of breast cancer as well as the difference of Ki-67 change among different molecular subtypes were analyzed. Results: Ki-67 expression before NCT was positively correlated to tumor size (r=0.181, P=0.047), histological grade (r=0.340, P<0.001) and HER-2 expression (r=0.335, P<0.001) of the patients. The 3-year disease-free survival (DFS) was 73.4%, which in patients with reduced, increased and unchanged Ki-67 expression after NCT was 82.6%, 61.1% and 68.4% respectively, and the difference was statistically significant (P=0.034), while among patients with different molecular subtypes was 70.7% for luminal A, 71.4% for luminal B, 80.7% for HER-2 positive, and 78.7% for basal like, and the difference had no statistical significance (P=0.857). Nationality, pre-treatment of HER-2 status, and pathologic axillary lymph node and change of Ki-67 expression after NCT were the independent influential factors for DFS of breast cancer patients (all P<0.05). Conclusion: The change of Ki-67 expression after NCT is an independent influential factor for DFS in breast cancer patients, but its change shows no obvious relation with breast cancer molecular subtypes.