Rejection of kidney transplantation is due to the fact that the human body has a sound immune system that can monitor the antigens that enter the body, including foreign grafts from the kidney, which will be recognized as antigens by the body’s immune cells and will produce the corresponding antibodies to attack, and after the attack, the antigens will be removed. If acute rejection occurs after kidney transplantation, the kidney will lose its physiological function and be rejected by the body in a short period of time. In the case of chronic rejection, there are many years in which the kidney will gradually fail and eventually lose its function. Therefore, kidney transplantation is recommended between relatives, because most of these cases are chronic rejection after transplantation. However, regardless of the type of kidney transplanted, rejection persists after transplantation, and chronic rejection occurs throughout the entire post-transplant procedure. Rejection is a removal of foreign antigens by the body’s immune system, unless the body’s immune system is broken and does not have a sound antigen recognition ability, such as when the body has acquired AIDS, at which time rejection will not occur.