Abstract: Objective To assess the value of serum crosslinked N-telopeptide of type I collagen （NTx） in the diagnosis of bone metastasis and prognosis of lung cancer and breast cancer. Methods PubMed， Cochrane Library， EMBase， CNKI， Wanfang database and VIP database were searched for collecting retrospective studies on serum NTx for diagnosis and prognosis of lung cancer and breast cancer. Studies were screened by the inclusion and exclusion criteria. QUADAS was used to evaluate the quality of the diagnostic studies. Stata 12.0 software was used to conduct the metaanalysis. Results Eleven literatures were selected， including 6 literatures in English and the others in Chinese， 8 studies about diagnosis， 2 studies about prognosis， and 1 study including diagnosis and prognosis were selected. A total of 1203 cases were identified， including 726 cases of lung cancer and 372 cases of breast cancer. The sensitivity and specificity of serum NTx in the diagnosis of bone metastasis from lung cancer and breast cancer were 76.5 ％ （95％CI： 61.5％-86.9％） and 83.3％ （95％CI： 77.1％-88.1％）， respectively. Merger HR estimate of overall survival for lung cancer and breast cancer patients with high serum NTx was 1.208 （95％CI： 1.128-1.293， P＜0.05）. Conclusion Despite the limitations of this study， serum NTx is a potential biomarker to detect bone metastasis and predict outcome in lung cancer and breast cancer. More prospective studies are necessary to analyze the clinical significance of serum NTx further.