In order to study the effects of traimcinolone acetonide on the wound healing of tongue, eight two healthy albino rats were asesthetized with pentothal. The wound, approximately 1mm in depth and 2mm in diameter, was created on the midlateral aspect of tongue with the tip of small rongeur fourcep. Forty one animals were employed in one of the following groups:(I) Control group: Received 0.5ml/100gm B.W. of saline suspension intralesionally at weekly interval until sacrificed.(II) Experimental group: Received $100mu extrm{g}/100gm$ B.W. of trimacinolone acet- onide suspension intralesionally at weekly interval until sacrificed. Biopsy specimens of wounds were taken at 6,18,24 hours, 2,3,5,7,14 and 28 days after wounding. The specimens were sectioned, and observed with light microscope and electron microscope. The results were as follows : 1. In the triamcinolone acetonide treated wound, the epithelial and fibroblastic regeneration were dealayed when compared with controls. 2. After triamcinolone acetonide treated, edema was decreased at the early stage of wound healing. 3. In the triamcinolone acetonide treated wound, the fibroblasts exhibited fine morphological changes and reduction of collagen formation. It seems that triamcinolone acetonide inhibits fibroblast function.