Abstract: Osteoarthritis (OA) is a chronic degenerative disease involving the entire joint. The pathogenesis and progression of OA bear close connection to the destruction and the abnormal metabolism of cartilage, subchondral bones and synovium. Platelet derived growth factor-AA (PDGF-AA) is a critical mitogenic and chemotactic factor for a variety of cells, including chondrocytes, mesenchymal stem cells, osteoclasts and osteoblasts, and PDGF-AA promotes effective wound repair. This paper reviewed the pathological changes of cartilage, subchondral bones and synovium in the process of OA development, and summarized research progress regarding the effect of PDGF-AA on the tissues and related cells mentioned above. Current studies have basically clarified the pathological changes of cartilage, subchondral bones and synovium in OA patients, and have shown that PDGF-AA serves critical regulatory function in the tissues or cells involved in OA, the internal mechanism of which remains unclear, though. More studies should be done to find ways to apply PDGF-AA for clinic purpose and to diagnose and treat OA on the cellular basis.