To investigate the effect of bone marrow mesenchymal stem cells (BMSCs) on the expression of TNF-α and NF-κB following traumatic brain injury (TBI).60 adult female SD rats were randomly divided into Sham groups,TBI groups, BMSCs treatment groups.Rats model of diffuse brain injury was established based on Marmarou method.Immunohistochemical and Western blotting were used to determine the espression of TNF-α and NF-κB.Behavioral tests were performed by Modified Neurological Severity Score (mNSS).Comparted with Sham group, TNF-α and NF-κB levels began to increase following TBI.Compared to the TBI group, the expression of TNF-α and NF-κB remarkably decreased in the BMSCs treatment group, The mNSS were significantly improved in BMSCs treatment group comparted with TBI.Our findings show BMSCs has a protective effect against TBI, which may be related to the inhibition of the expression of NF-κB and TNF-α.