Objective:To explore the migration,differentiation and the therapeutic effect of intracerebral transplantation of human mesenchymal stem cells (hMSCs) after hypoxic-ischemic brain damage in rats,and to test whether three anti-hMSCs monoclonal antibodies prepared by our group can detect hMSCs in rat brains.Methods: hMSCs were isolated and purified by density gradient centrifugation and adherence to culture flask.Cells of passage 3-5 were prelabeled with bromodeoxyuridine (BrdU) for 72 h before transplantation.Animal models of hypoxic-ischemic brain damage (HIBD) were built with 1 month old Wistar rats.Three days after hypoxia-ischemia,HIBD rats in hMSCs-treated group (n=18) received intracerebral transplantation of 5×105 hMSCs.In control group (n=18) HIBD rats received phosphate buffered saline of the same volume.In sham-operated group (n=6) and HIBD group (n=6),rats did not receive any transplantation.Rats in hMSCs-treated group and control group were allowed to survive for 0 day,3 days,1 weeks,2 weeks (all n=3) and 4 weeks (n=6,after transplantation).