Abstract: [Abstract] The tolerance of allograft has been considered the ultimate goal in organ transplantation.Although numerous protocols of allograft tolerance induction have been reported in mice，thus far，chimerism based on hematopoietic stem cell transplantation is the only reproducible scheme for inducing immune tolerance in human kidney transplantation.Transient immune chimerism or stable chimerism could induce renal allograft tolerance.Although persistent complete chimerism may reduce the risk of rejection，the development of graftversushost disease（GVHD）has limited its wide clinical application.In contrast，shortterm mixed chimerism does not lead to GVHD，but it is difficult to predict the risk of graft rejection after the disappearance of hematopoietic stem cell chimerism.Current efforts are aimed at developing clinically more feasible and reliable methods to induce persistent mixed chimeras in order to expand the clinical applicability of these treatment regimens.

Key words: chimera, kidney transplantation, haematopoietic stem cell transplantation, immune tolerance