The goal of this clinical trial is to explore the changes in the expression levels of inflammatory factors before and after the early treatment of Human Urinary Kallidinogen (HUK) in the acute ischemic stroke. It will also learn about the correlation between inflammatory factors and AIS prognosis, in order to clarify the efficacy and safety of Urinary Kallidinogen in the acute phase of AIS.

The study process lasts for a total of 90 days, including the screening period, treatment period, and follow-up period. During the treatment period, the experimental group is treated with HUK in the 48 hours of AIS plus routine clinical treatment, while the control group receives routine clinical treatment group for 7 days.All patients are followed up until the 90th day after stroke. The sample size of the study is 200 patients. The ratio of the experimental group to the control group was 1:1.

Inclusion Criteria:

1. Diagnosis as acute ischemic stroke according to the Chinese guidelines for diagnosis and treatment of acute ischemic stroke 2018;
2. First clinical onset or previous presence of cerebral infarction without severe sequelae（Premorbid mRS ≤2）
3. Age≥18 years, male or female;
4. 3≤Baseline NIHSS≤25;
5. Written informed consent obtained from the patient or legally responsible person.

Exclusion Criteria:

1. Cerebral hemorrhage and the acute phase of other hemorrhagic diseases；
2. Previously allergic or intolerant to injectable HUK；
3. Used ACEI drugs prior to medication and less than 5 half-lives of the drug (according to the specific drug instructions) or received ACEI drugs during the study period;
4. Stent surgery after the AIS onset or planned interventional therapy;
5. Pregnancy, lactation or planned pregnancy；
6. Life expectancy of less than 3months or inability to complete the study for other reasons；
7. Unwilling to be followed up or poor compliance；
8. Current participation in other clinical research;
9. Other causes of AIS (such as dissection, vasculitis, pre-thrombotic lesions, drug abuse).