Objective：To investigate the influence of core infarct volume on the prognosis of acute ischemic stroke with large vessel occlusion. Methods：Clinical and imaging data of patients with acute ischemic stroke who underwent endovascular therapy and/or intravenous thrombolysis from January 1，2020 to December 31，2021 in the Emergency Medicine Center of the First Affiliated Hospital of Nanjing Medical University were retrospectively analyzed. According to the change value of the National Institutes of Health Stroke Scale(NIHSS)score at admission and 72 hours after treatment，the patients were divided into the good prognosis group and the poor prognosis group. The characteristics of baseline data of the two groups were compared，and the risk factors for poor prognosis were analyzed by univariate and multivariate regression. The receiver operating characteristic(ROC)curve was constructed to analyze the predictive ability of core infarct volume on adverse prognosis. The relationship between core infarction volume and the probability of poor prognosis as well as odds ratio(OR)was plotted，and the trend of poor prognosis with core infarction volume was analyzed. Results：A total of 131 patients were enrolled，83 in the good prognosis group and 48 in the poor prognosis group. Baseline data showed that the core infarct volume in the good prognosis group was significantly smaller than that in the poor prognosis group(P= 0.041)，and endovascular therapy in the good prognosis group was higher than that in the poor prognosis group(P=0.040). Univariate regression analysis of poor prognosis showed that core infarction volume(OR=1.012，95% CI：1.004~1.021，P=0.006)，bleeding complications(OR=2.296，95% CI：1.028~5.181，P=0.043)，endovascular therapy(OR=0.310，95% CI：0.106~0.851，P=0.025)and bridging(OR=0.443，95% CI：0.203~0.930，P=0.035)were statistically significant. Multivariate regression analysis showed that core infarct volume(OR=1.013，95%CI：1.005~1.022，P=0.003)was an independent risk factor for poor prognosis. ROC curve indicated that core infarct volume(AUC=0.60，95%CI：0.50~0.71)had a good predictive value for poor prognosis. The non-linear curve showed that the prognosis was less affected by the volume of core infarction ≤31 ml. The prognosis was significantly affected by the volume of core infarction ＞ 31 mL. Conclusion：Core infarct volume is an independent risk factor for prognosis of ischemic stroke patients with occlusive large vessels