Objective: The adhesion molecule that mediate cell-cell and cell-extracellular matrix provides very important role in various physiologic and pathologic conditions, VLA integrin is heterodimeric transmembrane glycoprotein which participate in cell-cell and cell-extracellular matrix, especially collagen, laminin and fibronectin. Rheumatoid arthritis is important prototype of chronic inflammatory disease. Continuous emigration and anchorage of chronic inflammatory cells are prerequisite for the perpetuation of disease. Transient episode of inflammatory synovitis could be found in osteoarthritis also. Although the notion that VLA-integrin play a major role in the initiation and perpetuation of arthritis would be possible, distribution of VLA integrin in synovial tissue of rheumatoid arthritis and osteoarthritis was investigated by immunohistochemistry. Methods: Immunohistochemical analysis of synovial tissue utilizing avidin-biotin complex method was con- ducted. Applied monoclonal antibodies were CD49a-f, CD29, CD51, and CD61. The pattern of expression was scored by semiquantitative grading system. Results: 1) The expression of CD29 was diffuse and intense at synovial lining cells, endothelium and infiltrating inflammatory cells. Endothelial stain was evident with VLA-1, 6, CD51 and negative with VLA-4. Inflammatory cells expressed VLA-4, 5 intesively and synoviocytes expressed VLA-3, 5, 6 and CD51 as ligand for fibronectin and laminin. 2) CD29 expression of inflammatory cells were prominent around small blood vessles which showed strong stain of CD29 and located just beneath the synovial lining cells. 3) VLA-integrin expression in synvoium of osteoarthritis was smimilar to that of rheumatoid arthritis except little inflammatory cell infiltratilon and little proliferation of microvasculature. Conclusion: It was able to presume from above findings that VLA-integrin has been doing some role in the development and perpetuation of synovitis. Future perspectives in field of VLA-integrin may be exact process of intracellular signalling, functional aspect of integrin and regulation of expression by some cytokines and growth factors.