Objective     To investigate the distribution and migration of bone mesenchymal stem cells (BMSCs) in the brain after intravenous injection  into brain-ischemic rats and to explore the effects on the learning and memory in rats.      Methods     Bone mesenchymal stem cells from adult rats were cultured in vitro. Then the cells were labeled by Hoechst 33342 and infused into the adult rats on day 3  after the ischemia/reperfusion model was established by cerebral artery occlusion. Morris water maze test was used to explore the effects on learning and memory function of the rats at 3 weeks after transplantation. Fluorescence microscope was used to identify BMSCs in rat brains at 4 weeks after transplantation.      Results     All indices in Morris water maze test were significantly different from those of control group at 3 weeks BMSCs transplantation（P0.05）. BMSCs survived and localized to the ipsilateral ischemic hemisphere.      Conclusion     BMSCs are able to survive and migrate to ischemic brain tissue through intravenous transplantation and improve the learning and memory function of rats.