Objective:To investigate the effects of neural stem cell (NSC)transplantation combined with PEP-1-SOD1 on recovery of neurologic function of rats with traumatic brain injury. Methods:A total of 80 healthy SD rats were randomly divided into four groups including the control group (with injection of physiological saline into injury region),the NSCs transplantation group (suspension of NSCs),the SOD1 group (PEP-1-SOD1 protein),and the NSCs transplantation + SOD1 group (suspension of NSCs + PEP-1-SOD1 protein). AQP4 mRNA and AQP4 expressions were determined by quantitative polymerase chain reaction (QPCR)and Western blot assay at the 4th day after traumatic brain injury. Bederson neurobehavioral assessment was performed 24 hours,3 days,1,2,3 and 4 weeks after traumatic brain injury. Morris water maze test was performed to determine neurologic function of rats from day 23 to 28 after traumatic brain injury. Immunohistochemistry and pathology changes were determined at 4 weeks after injury. Results:The expressions of AQP4 mRNA and AQP4 in the control group were higher than those in the NSCs transplantation group and SOD1 group,and the expressions in the NSCs transplantation group and SOD1 group were higher than those in the NSCs transplantation+SOD1 group(P < 0.05). Bederson scores at 4 weeks after traumatic brain injury were lower than those at 24 hours in all groups. At 4 weeks after traumatic brain injury,the scores in the NSCs transplantation+SOD1 group were lower than those in the control group(P < 0.05). Morris water maze test showed that neurologic function in the NSCs+SOD1 group was significantly more improved than that in the control group (P < 0.05). Immunohistochemical staining showed that the number of BrdU positive cells in the NSCs transplantation+SOD1 group was higher than that in the control group,NSCs transplantation group,and SOD1 group(P < 0.05). Conclusion:PEP-1-SOD1 combined with transplantation of neural stem cells can significantly improve the neurological function in rats with traumatic brain injury.