Abstract: 【Abstract】Objective To determine whether the NgR gene silencing in BMSCs can enhance curative effects of transplantation by vein of BMSCs on cerebral infarction in rats . Methods BMSCs were cultured by the suspension culture in vitro, and were transfected by siRNA to knock down the expression of NgR. Western blot and were used to assess the knockdown efficiency. The models of cerebral infarction were made by Middle cerebral artery occlusion (MCAQ) and randomly divided into three groups, A group for the NgR gene silencing of BMSCs .B Group for the equivalent group of BMSCs suspension. C group was injected the same amount of non-stem cell of the culture medium. The neurological defect scores were determined after 24 h, 3 days and 1, 2 weeks after MCAQ. The immunohistochemistry and pathology were checked after 2 weeks . 【Result】Western blot approved that the expression of NgR was knocked down by transfection of siRNA at 24 hours after the transfection. The neurological defect scores were significantly lower in A group than those in the B and C group 1 weeks after MCAQ (P<0.05). The number of neurons in A group was higher than that in the B and C group(P<0.05) .Conclusion: The BMSCs of NgR gene silencing transplanted by vein into the cerebral infarction tissues can significantly improve the neurological function in the rats with TBI