he purpose of this study is to determine the efficacy and safety of remote ischemic conditioning for acute ischemic stroke.

In this study, 912 cases of ischemic stroke in 48 hours were included in 5 centers in China according to the principle of random, double-blind and parallel control .The experimental group receive basic treatment and remote ischemic conditioning for 200mmHg, 2 times per day for 7 consecutive days .The control group receive basic treatment and remote ischemic conditioning control for 60mmHg, 2 times per day, 7 days in a row . Two groups will be followed up for 90 days to evaluate the efficacy and safety of remote ischemic conditioning therapy.

Inclusion Criteria:

• 1）Age≥18 years, < 80 years, regardless of sex；
• 2）Patients with clinically definite diagnosis of acute ischemic stroke and able to commence RIC treatment within 12 hours of stroke onset
• 3）Baseline NIHSS score>5, and≤25 ；
• 4）GCS score ≥8；
• 5）Signed and dated informed consent is obtained

Exclusion Criteria:

• 1) Patients with suspected posterior circulation infarction；
• 2) Patients who undergo thrombolytic therapy or endovascular treatment；
• 3) mRS≥2 score before the onset of the disease；
• 4) Double upper limbs or lower limbs paralysis was found in this case；
• 5）Active bleeding of organs within 6 months of admission or current, including cerebral hemorrhage, subarachnoid hemorrhage, gastrointestinal hemorrhage, fundus hemorrhage and so on；
• 6) Other intracranial lesions, such as cerebrovascular malformation cerebral venous diseases, tumor and other diseases involving the brain；
• 7) Treated blood pressure ≤90mmHg/60mmHg or≥180mmHg/100mmHg；
• 8) Severe organ dysfunction or failure；
• 9) Persons suffering from severe hematological diseases or severe coagulation disorder dysfunction；
• 10) Those who had a history of severe trauma or had major surgery within 6 months prior to admission；
• 11) The patients who had the contraindication of remote ischemic conditioning treatment, such as severe soft tissue injury, fracture or vascular injury in the upper limb；Acute or subacute venous thrombosis, arterial occlusive disease, subclavian steal syndrome, etc；
• 12) Pregnant or lactating women；
• 13) Previous remote ischemic conditioning therapy or similar treatment；
• 14) Patients with a life expectancy of less than 3 months or patients unable to complete the study for other reasons；
• 15) Severe hepatic and renal dysfunction
• 16) Unwilling to be followed up or treated for poor compliance；
• 17) He/She is participating in other clinical research or has participated in other clinical research or has participated in this study within 3 months prior to admission；
• 18) Other conditions that the researchers think are not suitable for the group.