Study of rhPro-UK in Patients With Acute Ischaemic Stroke in 4.5 Hours After Stroke Onset(PROST)

Inclusion Criteria: 1. Ischemic stroke with symptoms of neurological deficits. 2. Aged 18 to 80 years（including the critical value）. 3. NIH Stroke Scale（NIHSS）scores of 4 to 25（including the critical value）. 4. Treatment within 4.5 hours after stroke onset. 5. The symptoms of stroke last at least 30 minutes without significant improvement before treatment. 6. CT showed negative or signs of early infarction. 7. Informed Consent Form signed by the patients or family (legal representatives) must be provided. Exclusion Criteria: 1. Patients with premorbid modified Rankin Scale (mRS) score ≥2 2. CT showed multiple infarctions（low density\> 1/3 cerebral hemisphere）. 3. Transient ischemic attack. 4. Epileptic seizure after stroke. 5. Intracranial tumor, arteriovenous malformation and aneurysm. 6. Iatrogenic Stroke. 7. Planned for thrombectomy. 8. Cardioembolism and atrial fibrillation. 9. Myocardial infarction history within 3 months. 10. Severe cerebral trauma or stroke history within 3 months. 11. Patients with systolic blood pressure ≥ 180mmHg or diastolic blood pressure ≥ 100mmHg after anti-hypertension treatment. 12. Intracranial hemorrhage or subarachnoid hemorrhage on baseline. 13. Active visceral hemorrhage. 14. Patients with intracerebral hemorrhage history. 15. Patients with diabetic retinopathy history. 16. Puncture in 1 week which can not be oppressed. 17. Major surgery or severe trauma within 2 weeks. 18. Intracranial surgery, intraspinal surgery or solid organ biopsy within 30 days. 19. Heparin treatment within 48h and increased APTT is above ULN. 20. Using of oral anticoagulant drugs and PT \>15s or INR \>1.7. 21. High risk of acute hemorrhage include platelet count\<10\^9/L. 22. Using of thrombin inhibitors or factor Xa inhibitor with abnormal results of sensitive laboratory examination. 23. Blood glucose \< 2.7 mmol/L or \> 22.2 mmol/L. 24. Pregnancy, lactating or menstrual women. 25. The investigator believes that the patient is not suitable for the study.