Disclosed is a pharmaceutical composition for treating bone disease or countering inflammation containing cartilage stem cells as an active ingredient. The present disclosure provides a novel cell treatment regimen for bone disease and inflammatory disease using the cartilage stem cells as an active ingredient. When the cartilage stem cells of the present disclosure are administered into the articular capsule, the administered cartilage stem cells are highly effective in treating bone disease and inflammatory bone disease since they grow or differentiate into chondrocytes and exhibit an anti-inflammatory activity. Since the cartilage stem cells of the present disclosure do not express histocompatibility antigens which give rise to rejection in tissue or organ transplants, autologous cells or exogenous cells can be used during cell transplantation for treatment of bone disease and inflammation.