Patients of vascular cognitive impairment-no dementia (VCIND) in one group is prescribed cilostazol,in the other group is prescribed aspirin. Evaluate both of them in cognitive function, MRI and other sides at given time. The investigators hypothesize that cilostazol is more efficient and safer than aspirin in patients with VCIND.

Inclusion Criteria:

1. Aged between 50-80, both gender；
2. Small vessel disease and associated cognitive impairment, diagnosed as VCIND；
3. Non-specific subjective symptoms (dizziness, somnolence, numbness in limbs) are acceptable.
4. Normal hepatic and renal function.
5. With good compliance.

Exclusion Criteria:

1. Aged above 80 or less than 50.
2. Dementia.
3. Cerebral infarction(>2cm).
4. Major vascular lesion. (stenosis>50%).
5. Cardiac cerebral infarction.
6. Intracerebral Hemorrhage.
7. Clinical manifestations cannot attribute to small vessel disease.
8. Major depression or dysfunction in speech, visual ability, hearing or aphasia that would interfere with the cognitive assessment.
9. Severe systematic organic impairment(cardiac, hepatic, renal dysfunction).
10. Thrombocytopenic Purpura.
11. History of hemorrhage in digestive system or surgery in past 3 months.
12. Previously on cilostazol treatment for more than 3 month.
13. Allergic to aspirin or cilostazol.
14. Enrolled in other clinical trials in past 3 months.
15. Lack of informed consent or compliance.
16. Contraindications for MRI scan.