Effective biomarkers for clinical usage of osteoarthritis are still limited. It was confirmed that C-terminal crosslinking telopeptide of type I collagen (CTX- II) was a specific marker reflecting degradation of articular cartilage. Detection of CTX- II could promptly reflect level of cartilage injury and degradation ,diagnose OA,predict its progress,monitor effects of drug treatment, thus, reflect the condition of osteoarthritis patient indirectly. Application of CTX- II focused mainly on in the early stage of OA and need together to detect with other biomarkers,in order to more accurately reflection of the pathological changes of OA,but the specific clinical significance of CTX- II results still need to improve further.