Breast cancer is by far the most common malignancy in females. And bone is the most common site of distant metastasis in breast cancer, accounting for about 65 to 75% of all metastatic breast cancer patients.1,2Bone metastasis is an important factor affecting the prognosis of breast cancer. When patients have early-stage breast cancer without metastasis, their 5-year survival rate is as high as 90%, and once metastasis occurs, their 5-year survival rate will drop to 10%.3 Bone radionuclide imaging (ECT), X-ray, CT scan, MRI and other imaging tests to diagnose breast cancer bone metastasis are commonly used in clinical, It is currently believed that breast cancer bone metastasis is a multistep process: first, breast cancer cells need to acquire invasive and metastatic properties; breast cancer cells enter the blood circulation and migrate from blood breast cancer cells enter the blood circulation and migrate from blood vessels to bone tissue in a targeted manner; breast cancer cells adhere and remain in bone tissue and colonise it; and finally, it leads to bone destruction.4 Several key molecules are involved in breast cancer bone metastasis, and serum biomarkers are generally able to detect pathological changes earlier Several key molecules are involved in breast cancer bone metastasis, and serum biomarkers are generally able to detect pathological changes earlier than imaging.5 This review describes the progress of serum biomarkers for breast cancer bone metastasis.