TGF-beta is one of growth factors that may be involved in the formation of bone and cartilage. Multiple studies demonstrate that TGF-beta is involved in regulating cell proliferation, differentiation and matrix synthesis, events observed in frature healing. The appearance of TGF-beta in the fracture during healing was evaluated by immunohistologic localization of TGF-beta using antibody. Twenty Sprauge-Dawly strain white male rats, each weighing about 150grams were used and divided two groups. The one group, the 2x2mm bony defect was formed in the fight femur. The other group, 4x2mm bony defect was forned in fight femur. Both group were sacrificed at 3day, 1,2,3,4 week and femur were harvested, paraffin sections were stained with H & E, MT stain, immunihistochemical staining with TGF-beta antibody and observed under light microscope. The result were as follows: 1. New bone formation and cartilagenous tissue was seen at 3day. And in the 2x2mm bony defect group, TGF-beta stained the cell surrounding new bone. 2. The osteoclast and trabecular was seen at 1week. TGF-betastained the osteoblast and in the 2x2mm bony defect group was stained more than 4x2mm bony defect group. 3. The lamella bone and trabecule was seen from 3,4 week, and TGF-beta stained almost negative. From the above finding, we could concluded that TGF-beta stained the osteoblast at early stage and 1week, the peak stain was seen from 1week, and then decreased, almost negative stain was seen at 3, 4week.