Objective To analyze the significance of urinary type Ⅰ collagen cross-linked N-telopeptides (uNTX) for the prognosis and response to therapy of bone metastatic neoplasms.Methods The subjects were divided into 3 groups: A,B and C.The levels of uNTX were measured by enzymatic immunoassay kit,and the activity of serum alkaline phosphatases(AKP) and calcium concentration were measured simultanuously.Results uNTX levels positively correlated with bone metastatic neoplasms,and were markedly high in the patients with extensive bone collagen breakdown.Conclusions uNTX is more sensitive than the activity of serum AKP and plasma calcium concentration for bone metastasis of neoplasms,so it is significant in differentiating and monitoring bone metastatic neoplasms.The measurement of uNTX is an early objective methods for evaluation of prognostic response to therapy of bone metastatic neoplasms.