The evaluation of the efficacy of breast cancer treatment, especially the effect of neoadjuvant chemotherapy, will directly determine the recurrence of breast cancer after surgery and influence the determination of the next treatment plan for the tumor. The following is a brief description of the follow-up of different breast cancer treatment modalities. Follow-up of patients undergoing neoadjuvant chemotherapy for breast cancer Mammography and ultrasonography are difficult to differentiate between tumor residual after chemotherapy and chemotherapy-induced fibrosis, while breast MRI has become the preferred method to evaluate the efficacy of breast cancer treatment because of its high soft tissue resolution and tomographic imaging. PET-CT can be used for post-treatment monitoring and follow-up, detection of local recurrence and distant metastases (re-staging), especially for patients with obvious bone metastases. For patients with mastectomy, regular ultrasound examination of the affected subcutaneous + contralateral breast and axilla should be performed, and for patients without axillary lymph node dissection, bilateral axillary ultrasound examination, chest CT examination and upper abdomen ultrasound examination can be performed if available. The efficacy of PET-CT can be evaluated for patients with obvious bone metastases. Follow-up of breast cancer patients after breast-conserving surgery The widespread use of breast-conserving treatment has significantly improved the quality of survival of breast cancer patients. In recent years, the proportion of breast-conserving surgery in China has been increasing year by year, and postoperative tumor remnants have become the biggest problem after breast-conserving surgery. Due to the more obvious postoperative hematoma and fibrous reaction, it is easy to conceal the residual tumor tissue. Therefore, MR is a better imaging method to evaluate tumor remnants. Therefore, for breast-conserving breast cancer patients, sexual breast ultrasound + mammography is recommended for follow-up, and annual breast MRI can be performed if available. Therefore, the various examinations are complementary, and the integration of multiple imaging methods has become an important guarantee for accurate diagnosis and precise treatment. Knowing the clinical indications for each test and choosing the best imaging protocol will not only truly benefit patients.