Abstract: To evaluate the benefits of using new bone metabolic markers such as urinary pyridinoline cross- linked N- telopeptides of Type I collagen (NTx) and serum pyridinoline crosslinked C- telopeptides of Type I collagen (ICTP) in the detection of bone metastasis in patients with malignant tumors. Methods: The levels of urinary NTx and serum ICTP in 77 patients with malignant tumors were measured using ELISA. Results: The level of all bone markers in patients with bone metastasis was significantly higher than in the patients without bone metastasis (P<0.01). Higher urinary NTx and serum ICTP were detected and a significant correlation was seen between the two markers (r=0.880,P<0. 01). The sensitivity, specificity and accuracy of urinary NTx was 82.5 %, 83.8% and 83.2% (P< 0.05), and the sensitivity, specificity and accuracy of serum ICTP was 87.5%, 73.0% and 80.6% (P<0.05), respectively. Strong linear associations were seen between the extent of skeletal infiltration and the levels of the two biomarkers (r=0.453, 0.475, P<0.01), but there was no significant correlation between the level of urinary NTx or serum ICTP and bone pain (r=0.010, 0.083, P>0.05). Conclusion: The measurement of urinary NTx and serum ICTP are of significant utility as biochemical markers of bone metastasis in patients with malignant carcinoma and can be used to achieve a timely diagnosis for bone metastasis of the malignant tumor.