Abstract: Objective To study the efficacy and safety of autologous bone marrow transplantation（ABMT）for type 1 diabetes mellitus（DM）. Methods Autologous bone marrow,collected from 16 type 1 DM patients,was stored in a refrigerator.The bone marrow preconditioned with cyclophosphamide and antithymocyte globulin was infused into type 1 DM patients through the veins.Dose of insulin,levels of HbA1c,C-peptide and blood glucose were measured,and adverse effects were recorded before and after ABMT. Results The patients were followed up for 62-365 days with a median follow-up time of 265 days.Insulin was withdrawn from 11（68.8%） of the patients 5-114 days after ABMT with a median time of 21 days and a longest time of 360 days.Two of the 11 patients after withdrawal of insulin received insulin again about 2 months after ABMT,the other 5 received a smaller dose of insulin after ABMT than before ABMT（P＜0.05）.The C-peptide level was significantly higher in the patients after ABMT than before ABMT（P＜0.05）.No severe adverse effects such as long-term myelosuppression occurred in any of the patients. Conclusion ABMT is effective and safe for type 1 DM patients and its long-term effect needs to be further confirmed.