Objective Clinical data of patients with ischemic stroke were analyzed to detect the level of miR-17-5p, miR-27b-3p, miR-92a-3p, miR-125a-5p, miR-186-5p, miR-208b-3p in serum and analyze the correlation between the stenosis and severity of the intracranial and extracranial arteries and the above miRNAs. Methods Ninety-nine patients in the Department of Neurology of The Affiliated Hospital of Southwest Medical University who were diagnosed with ischemic stroke were divided into a simple intracranial artery stenosis group (n=24) and a simple extracranial artery stenosis group (n=18) according to the scope of vascular stenosis, intracranial and extracranial artery stenosis group (n=24), and intracranial and extracranial artery stenosis group (n=33). RT-PCR was used to detect the levels of miR-17-5p, miR-27b-3p, miR-92a-3p, miR-125a-5p, miR-186-5p, miR-208b-3p in the serum of each group, and analyze the levels of miR-17-5p, miR-27b-3p, miR-92a-3p, miR-125a-5p, miR-186-5p, and miR-208b-3p. Clinical relevance. Results Compared with the control group, the expressions of miR-17-5p, miR-27b-3P, miR-92A-3P, and miR-186-5p in the clinical serum of patients with intracranial artery stenosis were significantly increased, while in the cranial artery stenosis group, the expression of miR-17-5p, miR-27b-3P, miR-92A-3P, and miR-186-5p were significantly increased. In the external artery stenosis group, the expression level of miR-125a-5p was significantly reduced (P＜0.05). In the serum of patients with severe stenosis, the expression level of miR-17-5p was only higher than that of mild stenosis group, the level of miR-27b-3p was higher than that of mild and moderate stenosis group, while miR-125a-5p was significantly higher Lower than the mild stenosis group. There was a differential expression of miR-92a-3p in the mild, moderate, and severe groups, but there was no statistical difference in miR-186-5p between the groups with different degrees of stenosis. Comparing the intracranial and extracranial artery stenosis group with the simple intracranial artery or extracranial artery stenosis group, the expression levels of miR-17-5p, miR-27b-3p, miR-92A-3p and miR-186-5p in the former's serum were significantly higher than The latter two are high. Conclusion Serum miRNAs change significantly in patients with ischemic stroke. miR-17-5p, miR-27b-3p, miR-186-5p, miR-125a-5p are closely related to intracranial and extracranial artery stenosis, while miR-17-5p, miR-27b-3p, miR-92A-3p, miR-125A-5p are correlated with the degree of intracranial and extracranial artery stenosis, and it is expected to provide new molecular markers for the diagnosis of intracranial and extracranial artery stenosis.