The present invention provides a novel therapeutic agent for graft-versus-host disease (GVHD). A therapeutic agent for graft-versus-host disease (GVHD), which comprises an interleukin 6 (IL-6) receptor inhibitor as an active ingredient.提供新穎的治療移植物抗宿主疾病(GVHD)用治療劑。以間白素-6(IL-6)受體抑制劑為有效成分之治療移植物抗宿主疾病(GVHD)用治療劑。