Apoptotic death of articular chondrocytes has been implicated in the pathogenesis of osteoarthritis. Tartrate resistant acid phosphatase (TRAP) has been used for several years as a marker enzyme of bone-resorbing osteoclasts. This study investigated the activity of TRAP in media of apoptotic cell death-induced canine chondrocyte. We exposed canine chondrocyte to capsaicin and the results showed that capsaicin induced cell death in a dose dependent manner. And we measured TRAP activity in media of chondrocyte death induced by capsaicin treatment and the results capsaicin significantly increased the activity of TRAP in media for dose dependent. We also investigated whether the combination treatment with capsaicin and TRAIL enhance apoptotic cell death in canine chondrocyte. We exposed canine chondrocyte to capsaicin for 24 hrs at the indicated dose, and then treated with recombinant TRAIL protein for 24 hrs. TRAIL alone did not induce cell death after 24 hours, but the combined treatment of both induced more cell death compared with capsaicin alone in a dose dependent manner. Also, the combination treatment with capsaicin and TRAIL increased the activity of TRAP in culture media. These results suggest that TRAP can flow out into extracellular after chondrocyte damage, and TRAP may be a successful biomarker for detection of joint disease such as osteoarthritis.