Cyclosporine A(CsA) is a powerful immunossuppresive agent used to prevent graft rejection of organ and treat autoimmune disease. One of the major side effects associated with CsA treatment is the development of gingival overgrowth. The purpose of this study was to evaluate the expression and association of the several growth factors in gingival overgrowth induced CsA using by immunohistochemical technique. Normal tissues as control were obtained from healthy normal gingivae and overgrowth gingival tissues as experiments were obtained from the patients taken the CsA. The expressions of the MMP-1, TIMP-1, TGF$eta$-1, p21, p53, PCNA were evaluated by immunohistochemical technique. The more overgrowth was detected at the epithelial and connective tissue area in experimental group. The MMP-1, TGF$eta$-1, p21, p53, PCNA expressions were significantly increased in experimental group. The TIMP-1 expressions was not significantly increased in experimental group. We could conclude that the gingival overgrowth induced CsA was related with the collagen matabolism in connective tissue and also the production of the growth factor from epithelial tissue.