Objective To explore the clinical significance of internal mammary nodes in diagnosis and treatment of breast cancer. Methods The research papers on internal mammary nodes at home and abroad were analyzed in order to summarize the distribution, metastasis, detection and the effects of clinical treatment of the internal mammary nodes in breast cancer. Results The internal mammary nodes mainly locate near the sternum, along with the internal mammary artery and vein in the thorax. They were prone to metastasize at early stage and the metastasis rate also increased with the increased number of axillary lymph nodes in breast cancer. It could influence the recovery of the breast cancer patients by taking biopsy and treatment to the internal mammary nodes. Conclusion The biopsy and treatment of internal mammary nodes are useful for the patients with breast cancer to avoid the recurrence and helpful to stage, treatment and prognosis judgement of the breast cancer patients.