Abstract: Objective: To explore the early changes of serum nerve axon-guiding factor-1 (netrin-1) in patients with aneurysmal subarachnoid hemorrhage (aSAH) and its prognostic value for aneurysm clipping.Methods: A total of 168 patients with spontaneous aSAH who received aneurysm clipping in Department of Neurology of Huanggang Central Hospital for the first time from October 2018 to December 2021 were selected as the research objects.Serum netrin-1 levels were detected by enzyme-linked immunosorbent assay at admission and at various time points (24 h, 48 h, 72 h) after admission.Prognosis was assessed by modified Rankin score (mRS) at discharge, 30 d and 90 d postoperatively, with mRS score≥3 defined as poor prognosis.Multivariate logistic regression model was used to analyze the influencing factors of prognosis after aneurysm clipping.Receiver operating characteristic curve (ROC) was used to analyze the efficacy of serum netrin-1 level in the diagnosis and prognosis of aSAH.According to the optimal cutoff threshold, aSAH patients were divided into low netrin-1 subgroup and high netrin-1 subgroup.Results: The serum netrin-1 levels in patients with aSAH were higher than those in healthy controls within 72 hours after admission (P＜0.001).With the extension of the onset time, the serum netrin-1 levels in patients with aSAH had a downward trend(P＜0.001).The area under ROC curve of serum netrin-1 level for the diagnosis of aSAH at admission was 0.776 (95% CI: 0.723-0.829), and at the optimal cutoff threshold(321.13 pg/mL), the sensitivity and specificity were 80.40% and 61.30%, respectively.Multivariate Logistic regression analysis showed that low serum netrin-1 level was an independent risk factor for poor 90-day prognosis in patients with aSAH(P＜0.05).In addition, the median death time within 90 days in low netrin-1 subgroup at admission was shorter than that in high netrin-1 subgroup (P＜0.001).Combined detection of netrin-1 level at admission could further improve the predictive efficacy of Glasgow Coma Scale(GCS)score at admission for poor prognosis in patients with aSAH 90 days later after aneurysm clipping (P＜0.001).Conclusion: Low serum netrin-1 at admission can be used as a candidate biomarker for prognosis 90 days later after aneurysm clipper surgery in aSAH patients, and can improve the efficacy of GCS score in predicting poor prognosis.