Abstract: The major complication after the allogeneic bone-marrowtransplantation is graft-vs-host reaction (GYHR),The cutaneous changes that occurred in the acute forms of GYHR were described is three patients, The GYI-IR developed after bone-marrow transplantation for two cases of aplastic anemia and one case of acute granulocytic leukemia. Two of the three patients developed mild form skin lesions as subtle, transient macular erpthema, The other appeared to have more severe type as generalized maculopapular exanthem associated with high fever and systemic spmptoms.Skin biopsy specimens in all three patients revealed focal acantholysis, extension of lymphocytes into the epidermis and necrosis of individual epidermal cells. One of these slides showed a necrotic keratincyte surrounded by two Ipmphocytes, so called satellite cell necrosis(SCN).This picture is an important clue for the diagnosis of GYHR. In addition the skin biopsy specimens from two patients exhibited the striking thickening of the dermis with hypertrophic and closely packed collagen bundles that appeared hyalinized with atrophy of sweat glands embedded to them.These peculiar pictures not correlative to the clinical appearance have not reported so far is the Iiteratures.