As a source of transplantable stem cells, the CD34+ subpopulation in human umbilical cord blood (HUCB) has been used extensively to treat some hematopoietic system diseases. However,whether CD34+ cells hold the therapeutic potential to cerebral ischemia is unknown. The purpose of this study was to observe the recovery of neural function after transplantation of CD34+ cells derived from HUCB into ischemic cerebral tissue in rats.