Abstract: Osteoarthritis is a type of chronic degenerative disease with pain as the most common symptom. Currently, no effective therapies can reverse its underlying process. Mesenchymal stem cells(MSCs) are capable of differentiating to various musculoskeletal tissues, and have been proposed as a potential regenerative cell therapy source for osteoarthritis. This review is to summarize the development of MSC-based therapies to osteoarthritis including the source, administration route, amount of MSCs required by treatment, and therapeutic effect. Argument and difficulties encountered are also discussed.