Disclosed is a composition for the treatment of cartilage or bone damage or loss or defect. The composition comprises mesenchymal stem cells separated from umbilical cord blood and/or mesenchymal stem cells proliferated and/or differentiated. The composition also comprise chondrocytes and/or chondroblasts, or osteocytes and/or osteoblasts, differentiated from the mesenchymal stem cells separated from the umbilical cord blood.