Abstract: Intravenous immunoglobulin (IVIG) is an immunoglobulin (Ig) isolated from the plasma of healthy human, and its main component is IgG. The mechanism of IVIG is complex, which may play a role via multiple pathways. For example, the combination of Fc fragment of IgG with various Fc gamma receptor (FcγR) regulates inflammatory response and autoantibody metabolism, and Fab fragment of IgG neutralizes multiple antigens and other molecules. IVIG may also inhibit complement activation and affect the balance of anti-inflammation and proinflammation among immune cells. In the treatment of diseases, IVIG constantly plays a role through multiple mechanisms simultaneously, primarily via one certain mechanism in different diseases. IVIG is commonly applied in the desensitization treatment of sensitized patients, ABO incompatible renal transplantation, antibody-mediated rejection and several infectious diseases. In this article, the mechanism of IVIG and its application in renal transplantation were reviewed.