Acute Graft-versus-host disease(aGVDH) after allogeneic hematopoietic stem cell transplantation is one of the meaningful issues in aspect of patient's recovery and survival. in recent years, the understanding of the pathology of GVHD is much important to prevent or treat aGVHD. additionally, (oral) mucositis is one of the problems in patients with high dose chemotherapy, and mucositis by high-dose chemotherapy is related to HMGB-1 as proinflamtory cytokines. HMGB1 is a nuclear protein acts as a transcription factor, but, if it was released to the outside of cells by damaged cell or necrotic tissues, it works as cytokines for promoter of inflammation and cancers. at this point, there are no reported articles about correlation of HMGB1 and aGVHD in human. recently, we have seen excessive secretion of serum HMGB1 in mouse model, then base on this results, we will check correlation of HMGB1 and aGVHD/ oral mucositis in human.