Abstract： Objective To observe the short-term efficacy and safety of autologous bone marrow mesenchymal stem cells transplantation on patients with early spinal cord injury.Methods A total of 64 patients of early spinal cord injury were collected from January 2008 to January 2011.The cases were divided into two groups:the transplantation group (n=35) treated by subarachnoid injection with autologous bone marrow mesenchymal stem cells,the control group (n=29) in the same period of hospitalization without transplantation.Two groups were evaluated with motor and sensory function according to the AISA score before transplantation and the first,the third,the sixth month after transplantation respectively.Meanwhile,blood routine,clotting function,biochemical items and tumor markers were also followed up.Results There was varying degree recovery of motor and sensory function in two groups at the first month after transplantation,and sensory function recovered obviously but no statistical differences were found between two groups.The score of motor function increased in both groups at the third month after transplantation,but still without statistical differences (P＞0.05).The score of sensory function of subarachnoid transplantation group (131.9±41.6) was significantly higher compared to control group (108.3± 36.4) (P＜0.05).The score of motor and sensory function in control group was not significantly increased at the sixth month after transplantation,while transplantation group patients got significant recovery compared with the control group (P＜0.05).The results of follow-up examination were not significantly abnormal.Conclusion The safety and recent efficacy of autologous bone marrow mesenchymal stem cells transplantation in treating early spinal cord injury by subarachnoid injection are certified.The long-term efficacy needs to be further studied.