Abstract: The present application relates to a use for cartilage regeneration and/or use for osteoarthritis treatment of a mesenchymal stem cell expressing TSG-6 protein. The present application provides a composition for cartilage regeneration and a pharmaceutical composition for osteoarthritis treatment, comprising a mesenchymal stem cell expressing TSG-6 protein as an active ingredient. The composition for cartilage regeneration and/or the pharmaceutical composition for osteoarthritis treatment provided by the present application can increase collagen expression of cartilage cells, reduce inflammation, and restore the cartilage structure.