It is known that TGF-beta induces scar in fetal wound healing. The fact gives us that inhibition of TGF-beta can reduce scar formation. It has been reported that neutralizing antibody of TGF-beta reduced scar in rat incisional wounds. Meanwhile decorin, which is main proteoglycan of extracellular matrix, has been known as other antagonist against TGF-beta. However there has been no report about effects of decorin on scar formation. This study examined the histologic findings and width of incisional wound of rat, which was treated with decorin, compsring with non treated wound. We found that scar width was narrower in wounds 2 and 8 weeks after incision and the amount of collagen fiber is less in wounds treated with decorin than in control group. The collagen fibers, especially in wound 8 weeks after incision, were thick and regularly arranged and similar to no dermis in wounds treated with decorin. These results suggest that decorin reduces scar formation and facilitates maturation in wound healing. Even though this study cannot confirm its mechanism, the effect of decorin might be due to inhibition of TGF-beta.