Objective:To explore the effects of the human neural stem cells(hNSCs) and human umbilical cord blood cells(hUCBCs)on the treatment of cerebral ischemic rats and the proliferation and differentiation status of these cells in the ischemic brain tissue of rats. Methods:HNSCs were separated from 10~13 weeks brains of spontaneous abortion human embryo and cultured;hUCBCs were gotten from the placentas of full-term babies;both hNSCs and hUCBCs were marked with BrdU(5 -滋mol/L) for two days. The middle cerebral artery occlusion(MCAO) rat models were made and the stem cells were injected into the tail vein one day later. The Neurological Severity Scores(NSS) tests were undertaken in all rats of the three groups at 0~35 days after injection. Immunohistochemical method was used to check the differentiation and migration of stem cells in vivo. Results:Neural stem cells from human embryonic brains had been successfully cultured,and found to form typical neurospheres in suspension. The hUCBCs had the capacity of proliferation in vitro. Twenty-one days later,the neurologic function of rats with injection recovered much better than those without injection,as evidenced by the NSS(P < 0.05). There was no statistical difference of NSS between the two injected groups at every time point before and after injection(P > 0.05). Within the brain tissue,BrdU positive cells were distributed throughout the damaged brain of recipient rats,the majority of these cells localized in the ischemic hemisphere,few of these cells were observed in the contralateral hemisphere(P < 0.05). Significantly more BrdU positive cells were found in the brain tissue at the 21,28 and 35 days points respectively than that at the 14th days after injection(P < 0.05). More BrdU positive cells were found in the rats received hNSCs the rats injected with hUCBCs. Nestin positive cells were found within the damaged brains at every time point. Among all the BrdU positive cells of hNSCs group,73.8% of these cells were positive for the astrocyte marker glial fibrillary acidic protein(GFAP),16.7% were positive for the CNPase and 9.5% expressed the neuronal markers neuron specific enolase(NSE). Among all the BrdU positive cells of hUCBCs group,74.5% of these cells were positive for GFAP,15.4% were positive for CNPase and 10.1% expressed NSE. There was no statistical difference between the two groups(P > 0.05). Conclusions:HNSCs and HUCBCs had multipotential differentiation properties in vivo and differentiated into three main types of neural cells by the influcence of the ischemic microenvironmental signals. Intravenous injection of hNSCs and hUCBCs could effectively improve the neurologic function of ischemic rats. Besides of hNSCs,hUCBCs injection may be an efficient method to treat ischemic cerebrovascular disease.