1.Breast cancer with multiple lesions and distant metastases should be excluded before surgery. Stage I and II breast cancer with a single lesion ≤ 3 cm in diameter and without skin and pectoral muscle adhesions. As Chinese breasts are not as large as western women, most of them advocate that the maximum diameter of breast cancer should not exceed 3cm. At present, the best indication for breast-conserving surgery is early-stage breast cancer with a maximum diameter of ≤2cm. 2. The ratio of tumor to breast volume is small, with the ratio of tumor to breast size between 1/4-1/6 is good. If the ratio is small, breast-conserving surgery is still feasible even if the tumor is larger than 3cm. 3.Scattered plexiform microcalcified lesions that can be completely removed locally. 4.Tumor located outside the areola area, and the mass is more than 2cm away from the nipple, among which those located in the outer upper or outer lower quadrant are safer. Because of the rich lymphatic vessels in the nipple areola area, lymphatic metastasis can easily occur at an early stage, and the tumor in this area cannot preserve the nipple, so breast conservation is not suitable for breast cancer in this area. 5. The patient has good psychological quality and voluntarily accepts breast-conserving surgery treatment. In China, the number of breast cancer patients who undergo breast-conserving surgery is still relatively small, which is due to the concern about the radicality and local recurrence rate of breast-conserving surgery. Breast-conserving surgery is feasible for some stage III breast cancers after neoadjuvant chemotherapy. 7.With radiotherapy equipment and technology. Because postoperative comprehensive treatment is an important factor to guarantee the effect of surgery. 8.Breast-conserving surgery has no special restrictions on pathological type and axillary lymph node status. However, patients with tumors containing extensive intraductal components (EIC) should be cautious, and some people believe that EIC should be a contraindication to breast-conserving surgery.