Organ transplantation has revolutionized the treatment for end-stage organ failure. Immunosuppression is still a major approach currently used in the prevention and treatment of allograft rejection. Both editors Dr. Chen and Dr. Qian have been contributing to preclinical evaluation of immunosuppressants for more than 25 years in North America. Experts from the United States, Canada, the United Kingdom, China, Japan, Germany, Sweden, Hungary and Brazil contributed 23 chapters to this book, providing details of immunological basis in transplantation. They also describe six classes of immunosuppressive agents (calcineurin inhibitors, mTOR inhibitors, JAK-STAT inhibitors, antiproliferative agents, costimulation blockers and corticosteroids), as well as ischemia/reperfusion injury treated agents. Additionally, the new development of cell therapy in the induction of transplant tolerance is introduced. This book provides many important references for the research direction of novel immunosuppressants. Readers that will find this book useful include transplant physicians, surgeons, nurses, immunologists, pharmacologists, pharmacists, medical students, residents and trainees in transplantation.