The present invention relates to : a composition for preventing and treating transplant rejection reactions or post-transplant immune diseases, which contains an SD282 compound or a calcineurin inhibitor; and various applications thereof. As a result of a single or combined treatment of the SD282 compound or FK506, one of calcineurin inhibitors to an allogenic model in vivo or in vitro, it is possible to inhibit T cell proliferation, decrease Th1 cell or Th17 cell activity, and inhibit inflammatory cytokines, thereby being able to be used in related pharmaceutical fields by inhibiting transplant rejection reactions and preventing and treating immune diseases that can occur after transplantation.COPYRIGHT KIPO 2019