Abstract： Objective To analysis the relationships between bone markers, bone-specific alkaline phosphatase (BAP) and cross-linked telopeptide of type Ⅰ collage (ICTP), and bone metastasis of breast cancer.Methods A total of 217 patients' serum were collected.The 217 cases were divided into two groups:109 cases with bone metastasis, 108 cases without bone metastasis. Serum BAP and ICTP was measured by ELISA. The relationships between factors of bone metastasis and serum levels of BAP, ICTP were analyzed.Results The levels of serum BAP and ICTP in bone metastases group were significantly higher than those in non-bone metastasis group[BAP:24.8 μg/L(7.60-213.70 μg/L) vs 21.2 μg/L(7.3～68.8 μg/L),ICTP:7.0μg/L(1.4～32.4 μg/L) vs 4.1 μg/L(0.0～15.8 μg/L) (P=0.003,P=0.000)].The level of serum BAP and ICTP in patients with multiple bone metastasis was significantly higher than that in patients with single bone metastasis[BAP:32.3 μg/L(9.A～213.7 μg/L) vs 18.1 μg/L(7.6～60.0 μg/L),ICTP:7.6 μg/L(1.4～32.4 μg/L) vs 4.9 μg/L(1.8～10.5 μg/L),(P=0.001,P=0.010)].The sensibility of BAP and ICTP was 45.0 ％ (49/109)and 46.8 ％ (51/109),respectively.The specificity of ICTP and BAP was 83.3 ％ (90/108)and 84.3 ％ (91/108),respectively.Joint detection of BAP and ICTP had improved sensibility in the diagnosis of bone metastasis in breast cancer patients. Conclusion Joint detection of serum bone biochemical markers ICTP and BAP have a little values for diagnosing bone metastasis in breast cancer patients.