Objective To investigated the distribution of epidermal stem cells in rat fullthickness wound tissues during the wound healing process and toelucidate the roles of epidermal stem cells in wound repair in vivo.Methods Eighty circular fullthickness wounds were produced on both sides of the back in 20 male Wistar rats labeled with BrdU 60 days previously (4 wounds in each rat). BrdU, β1 integrin and keratin 19 (K19) were employed to determine the epidermal stem cells with SP immunohistochemical methods, and the epithelialization wasdetermined with routine histological methods of HE staining on the 3rd, 7th, 14th, and 21st days after operation.Results No cells with positive immunostaining for β1 integrin, K19 and BrdU were found in granulation tissue of woundin both groups during the healing process. However, a few scattered β1 integrin and K19 positive cells were found within the stratum spinosum and stratum granulosum of the epidermis on the wound edges on the 3rd day post-injury. And these positive cells gradually became more and more in number, and mostly concentrated on the border of wound edges till the wounds healed. In addition, the number of positive cells for β1 integrin and K19 in the infected wounds was less than that in non-infected wounds. These positive cells for β1 integrin and K19 staining on the wound edge were also positively stained with BrdU in the cellular nuclei. Conclusion The above results indicate that ectopia of epidermal stem cells present a major function during wound epithelialization.