Inclusion Criteria- Age:greater than or equal to 18 years old and less than or equal to 70 years old;
- Time of onset is less than 7 days;
- Acute cerebral infarction due to the stenosis or occlusion of middle cerebral artery diagnosed by CT or MRI;
- The National Institute of Health Stroke Scale(NIHSS) score is 4 to 20;
- Excluding intracranial hemorrhage using CT or MRI.
Exclusion Criteria- The NIHSS score is less than or equal to 3;
- Patients with cerebral aneurysm, cerebral hemorrhage, brain tumor, brain contusion and laceration of brain and other diseases;
- Intracranial hemorrhage displaying by CT or MRI; Cardiac insufficiency;
- Cardiac insufficiency;
- Chronic liver disease(A/G inversion),elevated alanine aminotransferase(ALT)(more than 1.5 times the normal value);
- Increased serum creatinine(more than 1.5 times the normal value);
- Poorly controlled diabetes;
- Recently suffered from hemorrhagic disease or bleeding tendency;
- Recent use of angiotensin-converting enzyme inhibitor (ACEI) drugs;
- Allergic constitution and had a variety of drug allergy history;
- Women in period of pregnancy or lactation.