Objective： To study the sensitivity and clinical significance of HE-staining，IHC and RT-PCR in detecting breast cancer micrometastases in bone marrow and sentinel lymph nodes（SLNs）. Methods：After general anesthesia， all patients underwent bone marrow puncture and sentinel lymph node biopsy（SLNB） by 1% isosulfan blue， and then HE-staining，IHC and RT-PCR were used to detect micrometastases. Results：Of 62 patients with breast cancer whose axillary lymph nodes showed negative HE-staining results， 15 cases presented with positive RT-PCR and 9 cases showed positive IHC results positive in bone marrow micrometastases detection. PT-PCR and IHC showed good uniformity（kappa=0.6945）and there was significant difference in detective rate between these two methods（χ2=4.1667，P = 0.0412）. In SLN samples， 13 showed positive RT-PCR results， while 7 showed positive IHC results. PT-PCR and IHC showed good uniformity（kappa=0.6483）and significant difference was also found in detective rate between these two methods（χ2=4.1667，P = 0.0412）. Both bone marrow and SLN samples were RT-PCR positive in 3 cases， which indicated that bone marrow micrometastases did not always accompany SLN micrometastases（χ2=0.067，P = 0.796）. Conclusion： Even if no axillary lymph node involvement or distant metastases are present in routine preoperative examination， micrometastases can still be detected in bone marrow or SLNs. Because the bone marrow micrometastases and axillary node micrometastses are not present simultaneously， combination test of multiple indicators will detect micrometastases more accurately.