The objective of the study is to determine the safely of Human Umbilical Cord Blood mononuclear cells by Intravenous injection in acute ischemic stroke patients.

The study will use Umbilical Cord Blood cells (a special kind of cell that is believed to be a stem cell) isolated from UCB (blood obtained at birth from the umbilical cord blood of babies). StemCyte, a leading accredited UCB banking company with branches in the United States and Taiwan, will provide the units of UCB that match at least 4 out of 6 HLA (human leukocyte antigens) for transplantation. The HLA-matching is the same as that used to match cells and organs for transplantation so that the body does not reject the cells. Then cells injection by Intravenous in acute ischemic stroke patients.

Inclusion Criteria:

1. The age of Subjects between 45 through 80 years.
2. Acute Ischemic Stroke.
3. National Institutes of Health Stroke Scale (NIHSS):6-18
4. Brain MRI shows the middle cerebral artery region (M1 and M2) of cerebral i infarction stroke patients.
5. Subjects have no midline shift or hemorrhagic transformation

Exclusion Criteria:

1. NIHSS score reduced more than 4 within after 24 hours.
2. Female are pregnant or lactating.
3. Subjects with impaired liver function, AIDS, cancer or other significant medical condition (including certifiable diseases, rare disease)
4. Subjects joined other clinical trails or received rt-PA therapy.
5. Immune dysfunction or receiving other immunosuppressive agents.
6. Subjects cannot have MRI test
7. Subjects' HLA typing results match less than 4 out of the 6 genotypes