Objective To analyze the incidence of Epstein-Barr virus (EBV) infection in patients after allogeneic hematopoietic stem cell transplantation (HSCT),and investigate its risk factors and prognosis.Methods A total of 402 patients receiving HSCT were retrospectively studied from November 2011 to November 2014 in the 307th Hospital of Chinese People's Liberation Army.The cumulative incidence (CI) of EBV infection and survival rate were analyzed by Kaplan-Meier method,while risk factors were assessed by logistic regression model.Results The one-year CI of EBV viremia and post-transplant lymphoproliferative disease (PTLD) were 42.0％ and 1.5％,respectively.Using antithymocyte globulin (ATG) (P ＜ 0.001,OR =9.92) and acute graft-versus-host disease (GVHD) grade Ⅲ to Ⅳ (P ＜ 0.01,OR =2.42) were related risk factors of EBV viremia.There was a higher CI of EBV viremia in patients with 2 risk factors compared with those without (87.5％ vs 24.6％,P ＜0.001).Patients with EBV viremia had significant shorter three-year overall survival than patients without (58.5％ vs 75.4％,P ＜ 0.001).Conclusions The incidence of EBV infection in patients undergoing HSCT is high,which poses a threat on prognosis.Risk factors of EBV viremia include administration of ATG and severe acute GVHD.