Abstract: Objective To study the clinical features, diagnosis, treatment and prognosis-related factors of breast cancer lung metastasis 10 years after operation. Methods Clinical data (clinical features, diagnosis, differential diagnosis, treatment and prognosis) about breast cancer lung metastasis patients who underwent operation from 1997 to 2013 were retrospectively analyzed. Results The median age of 36 breast cancer lung metastasis patients was 55, the average lung metastasis time was (14.27±2.16) years. No significant difference was found in the age of breast cancer lung metastasis patients, and tumor pathologic type, axillary lymph node metastasis, progesterone receptor (PR) expression in breast cancer lung metastasis patients, postoperative chemotherapy and radiotherapy plan for breast cancer lung metastasis patients 10 years after operation (P> 0.05). However, the preoperative clinical staging of breast cancer lung metastasis, estrogen receptor (ER) expression in breast cancer lung metastasis patients, and endocrine therapy for breast cancer lung metastasis patients were significantly significant (P< 0.05). The median overall survival time of the patients was 22.5 (5-79) months, and the median time to progression was 11 (3-77) months. Metastasis to other sites, the number of pulmonary metastatic tumors, maximum diameter and chemotherapy cycles of metastatic tumor were related with the prognosis of breast cancer lung metastasis patients (P< 0.05). The overall survival time was 53.4 (24-79) months and the median time to progression was 42 (21-77) months in 6 patients with single focal pulmonary metastasis after surgical resection. Conclusion The prognosis of breast cancer lung metastases 10 years after operation is closely related with the number, size and treatment modalities of metastatic breast cancer. Its early diagnosis, comprehensive chemotherapy, radiotherapy, surgical and endocrine treatment can achieve rather good effects.