 This study is designed to investigate the efficacy and safety of allogeneic bone marrow-derived mesenchymal stem cells BM-MSCs on chronic antibody-mediated rejection cAMR after kidney transplantation. Chronic AMR is diagnosed according to Banff criteria 2013 based on renal graft biopsy and donor specific antibodies DSA examination. cAMR patients are assigned to MSCs group or control group. Patients in control group are prescribed to current desensitization therapy including at least one of the following treatments: plasmapheresis PP, intravenous immunoglobulin IVIG, rituximab or Bortezomib, depending on individual pathological and immunological features eg. DSA type and titer of each study subjects. Patients in MSCs group receive additional BM-MSCs therapy besides desensitization treatments as in control group. Allogeneic BM-MSCs 1106kg are intravenously administered every two weeks for four consecutive doses. All cAMR patients are followed up for one year. Renal function, DSA level, pathological features, patientgraft survival, and severe adverse events are monitored during the follow-up period. Immunological features of patients in both groups are consecutively examined. 