Destruction of cartilage in rheumatoid arthritis (RA) is mediated mainly by proteinases which can degrade cartilage matrix including type II collagen and aggrecan. Of these proteinases, matrix metalloproteinases (MMP) play significant roles in RA pathology, however recent studies show that a disintegrin and metalloproteinase (ADAM) families are another candidates. These proteinases are mainly produced from synovial cells and inflammatory cells, and concentrations of these proteinases in synovial fluid are significantly higher in RA than in OA. Several proteinases have been shown to express in chondorocytes of RA and these chondrocytic proteinases are thought to mediate cartilage destruction in RA. Apoptosis which is mediated by nitric oxide (NO) is another pathway of cartilage destruction in RA.