Objective:To investigate whether the results of anterior lymph node biopsy of breast cancer after neoadjuvant chemotherapy are true and reliable. Methods: Sixty patients with breast cancer were treated with 2-3 courses of neoadjuvant chemotherapy before surgery; 48 patients were treated with CEF (cyclophosphamide 60mg/m2, epirubicin 70mg/m2, fluorouracil 60mg/m2) and 12 patients were treated with CET (cyclophosphamide 50mg/m2, epirubicin 50mg/m2, doxorubicin 75mg/m2). The total number of lymph nodes and the number of blue-stained lymph nodes were counted in the resected specimens, and routine pathological examination was performed simultaneously with the gross specimens. Results: Among 66 patients with breast cancer, 60 cases of sentinel lymph nodes were stained successfully (90.9%), and the average number of sentinel lymph nodes examined was 1-5 per case. 8 patients whose tumors had been partially excised before surgery had their sentinel lymph nodes stained successfully. 23 of the 60 patients had positive cancer metastasis in their sentinel lymph nodes, of which 15 had positive lymph nodes in the axilla and 8 had negative lymph nodes. Among the 37 patients with negative sentinel lymph nodes, 35 patients had negative axillary lymph nodes and 2 patients had positive lymph nodes (5.4% of the patients had false negative sentinel lymph nodes), and the false negative rate was 8%. 48 patients with CEF protocol had 1 false negative sentinel lymph node, and 12 patients with CET protocol had 1 false negative sentinel lymph node. The metastatic status was accurately predicted in 58 of 60 patients. Conclusion: The pathological findings of the anterior sentinel lymph node examination in breast cancer patients treated with neoadjuvant chemotherapy with CET or CEF regimens also accurately reflected the metastatic status of axillary lymph nodes.