Inclusion Criteria:

1. Ischemic cerebral infarction or TIA within 30 days.
2. Aged above 18 years old.
3. Hospitalized.
4. Cranial CT or MRI scan exclude intracranial hemorrhagic diseases
5. Stable clinical and neurological conditions.
6. A Modified Rankin score less than 4 at enrollment
7. Informed consent is obtained.

Exclusion Criteria:

Patients will be excluded from entry if any of the criteria listed below are met

1. Documented stroke caused by conditions other than atherosclerosis, ie, surgical or vascular intervention procedure.
2. Severe co-morbid or unstable medical condition, ie, heart failure, respiratory failure and renal failure, severe liver dysfunction, malignancy with likelihood of death within the next 2 years
3. Significant memory or behavioural disorder, ie, Alzheimer disease, etc, daily care needed.
4. A Modified Rankin score is more than 4
5. Concurrent participation in another clinical trial
6. Pregnant
7. Unable to give informed consent.