Acute ischemic stroke registry--Xuanwu Hospital(XSR) is an academic, independent, prospective, single center, observational registry study. Consecutive acute ischemic stroke patients assessed in stroke "green channel" of Xuanwu Hospital(China) will be enrolled in our study. Patients receive regular treatment and data will be collected as part of clinical routine. Baseline clinical and procedural information as well clinical follow-up information during in-hospital stay, and up to 90 days of stroke onset are collected. Data collected include demographics, National Institute of Health Stroke Scale (NIHSS) on admission, pre-treatment ASPECTS, information on timing and success of thrombolysis or thrombectomy, procedural complications, intracranial hemorrhage, and functional outcome.The study aim to investigate the real situation of assessment, diagnosis and treatment of acute ischemic stroke patients in "green channel",and verify the effect of the improvement of "green channel" process in the diagnosis and treatment of patients with acute ischemic stroke.