Objective To establish a bone marrow stem cell bank and apply third-party bone marrow stem cells to treat chronic graft nephropathy and observe the clinical efficacy. Methods To obtain 100-200 ml of donor bone marrow components, extract single nucleated cells, perform cell counting, viability identification and CD34+ cell counting, and store at -80°C to establish a bone marrow stem cell bank. From 2010 to the present, patients clinically diagnosed with chronic graft nephropathy were divided into: (1) control group (20 cases); (2) stem cell treatment group (15 cases). The inclusion criteria were blood creatinine 170-300 μmol/L (2-3 mg/dl) and 24-hour urine protein quantification 300 mg-2000 mg. Patients in the stem cell treatment group received thawed bone marrow cell infusion with a cell count of 108-109 by slowly infusing a total volume of 50 ml of cell suspension at 10 min after localization of the renal artery from the femoral artery intervention. Peripheral blood CD45+ and CD34+ cell counts were monitored postoperatively, and changes in blood creatinine and 24-hour urine protein quantification were detected. The original immunosuppression regimen used in both groups remained unchanged, and the intensity of immunosuppression was not adjusted. The clinical efficacy of third-party bone marrow stem cell therapy for chronic graft nephropathy was determined at one year follow-up. Results Donor bone marrow component single nucleated cell counts were 5×108-109 per copy, active cell ratio was >90%, and CD34+ cells accounted for 0.01-0.05% of CD45+ cell count. After thawing, the cells were stored in 50 ml of blood cell storage solution with a cell count of 108-109 per serving, an active cell ratio of 70-80%, and CD34+ cells accounting for 0.01-0.02% of the CD45+ cell count. Patients in the stem cell treatment group received bone marrow stem cell treatment before peripheral blood CD34+ cells accounted for 0.01% of CD45+ cells, 0.05%-0.3% 3 days after treatment, 0.03%-0.2% 7 days after treatment, 0.03%-0.1% 1 month after treatment, 0.02%-0.05% 3 months after treatment, 0.01%-0.02% 6 months after treatment; 3 months after treatment Blood creatinine decreased by 20-100μmol/L compared with that before treatment, with a mean of 35(2-3mg/dl), and the mean of blood creatinine still decreased by 25μmol/L compared with treatment in 12 months after treatment; the mean of 24-hour urine protein quantification decreased by 300mg in 12 months after treatment. there was no improvement in renal function in the control group at the one-year follow-up after surgery. Conclusion After the establishment of bone marrow stem cell bank, there is still a need for technical improvement in the control of cell quality and quantity in the cell thawing process; the application of third-party bone marrow stem cell therapy can improve the renal function of patients with chronic graft nephropathy and can be an alternative new treatment tool. The detailed mechanism needs to be further explored.