Objective To investigate the association of miRNA-3177-3p with cerebral vasospasm （CV） and its clinical significance by measuring the expression of miRNA-3177-3p in cerebrospinal fluid （CSF） in patients with or without CV after aneurysmal subarachnoid hemorrhage （aSAH）.Methods A total of 29 aSAH patients were divided into CV group and non-CV group. General clinical data were compared between the two groups； miRNA-3177-3p was determined as the target miRNA after integrated bioinformatics analysis， and the expression of miRNA-3177-3p in CSF was measured and compared between the two groups； after ATP1B3 was predicted as the downstream target gene of miRNA-3177-3p， ATP1B3 plasmids were constructed and the dual-luciferase reporter gene assay was used to verify the targeting relationship between miRNA-3177-3p and ATP1B3； finally， ELISA was used to measure the content of ATP1β3， a transcription product of ATP1B3， in CSF， which was then compared between the two groups.Results The CV group had a significantly higher Hunt grade than the non-CV group （P <0.05）. There was a significant difference in the expression level of miRNA-3177-3p in CSF between the CV group and the non-CV group （0.873±0.044 vs 0.908±0.034， t = 2.157， P = 0.040）. The dual-luciferase reporter gene assay showed that after interaction with miRNA-3177-3p， the activity of ATP1B3-3′UTR region was reduced by 15% compared with the control group （P <0.05）， while the activity of ATP1B3-3′UTR region was increased by 14% after mutation （P <0.05）. ELISA showed that the CV group had a significantly higher level of ATP1β3 in CSF than the non-CV group （1.776±0.013 ng/mL vs 1.722±0.016 ng/mL， t = 7.778， P = 0.000）.Conclusion The expression level of miRNA-3177-3p is downregulated in CV patients， and the high expression of its target gene ATP1B3 may be involved in the pathogenesis of CV. This mechanism may have a certain clinical significance in the prediction and treatment of CV. ［Journal of International Neurology and Neurosurgery, 2023, 50(3): 6-11］