Objective:To explore the influence of blood pressure during peri-thrombolysis period (from admission to 24 h after thrombolysis) in intracranial hemorrhage, improvement of neurological function, primary endpoint event (recurrence of symptomatic stroke) and secondary endpoint events (complex cardiovascular and cerebrovascular events, and all-cause death) in patients with acute ischemic stroke.Methods:A total of 422 patients with acute ischemic stroke who underwent intravenous thrombolysis with alteplase during hospitalization at National Center for Stroke in Lianyungang from January 2015 to March 2019 were followed up for 90 d. According to the quintile of mean systolic and diastolic blood pressures during peri-thrombolysis period, they were divided into group of blood pressure <130.00 mmHg (Q1), group of blood pressure of 130.00-140.49 mmHg (Q2), group of blood pressure of 140.50-147.99 mmHg (Q3), group of blood pressure of 148.00-158.00 mmHg (Q4), and group of blood pressure >158.00 mmHg (Q5), and group of blood pressure <71.30 mmHg (G1), group of blood pressure of 71.30-76.19 mmHg (G2), group of blood pressure of 76.20-81.89 mmHg (G3), group of blood pressure of 81.90-90.79 mmHg (G4), group of blood pressure >90.79 mmHg (G5). Univariate and multivariate Logistic regression analyse were used to evaluate the relations of blood pressure with postoperative intracranial hemorrhage and neurological function improvement. Kaplan-Meier curve, Log-rank test and multivariate Cox proportional risk model were used to evaluate the relations of blood pressure with primary endpoint event and secondary endpoint events.Results:(1) After adjusting for confounding factors, multivariate Logistic regression analysis showed that the risk of postoperative intracranial hemorrhage in patients from Q2 was significantly lower than that in patients from Q5 ( OR= 0.160, 95%CI: 0.031-0.827, P=0.029). (2) After adjusting for confounding factors, multivariate Logistic regression analysis showed that the probability of postoperative improvement of nerve function in patients from Q2 and Q3 was significantly higher than that in patients from Q5 ( OR=2.144, 95%CI: 1.043-4.407, P=0.038; OR=2.224, 95%CI: 1.105-4.479, P=0.025); the probability of postoperative improvement of nerve function in patients from G3 and G4 was significantly higher than that in patients from G5 ( OR= 2.153, 95%CI: 1.081-4.287, P=0.029; OR=2.182, 95%CI: 1.131-4.210, P=0.020). (3) After adjusting for confounding factors, multivariate Cox proportional risk model showed that the risk of primary endpoint event in patients from Q1 and Q2 was significantly lower than that in patients from Q5 ( HR=0.079, 95%CI: 0.010-0.613, P=0.015; HR=0.211, 95%CI: 0.062-0.724, P=0.013). (4) After adjusting for confounding factors, multivariate Cox proportional risk model showed that the risk of secondary endpoint events in patients from Q1, Q2, Q3 and Q4 was significantly lower than that in patients from Q5 ( HR=0.246, 95%CI: 0.100-0.607, P=0.002; HR=0.360, 95%CI: 0.177-0.732, P=0.005; HR=0.448, 95%CI: 0.246-0.817, P=0.009; HR=0.467, 95%CI: 0.252-0.867, P=0.016). Conclusion:The risks of postoperative intracranial hemorrhage, primary endpoint event and secondary endpoint events in patients with acute ischemic stroke decrease with the decrease of systolic blood pressure during peri-thrombolysis period; moderate blood pressures (systolic blood pressure: 130.00-147.99 mmHg; diastolic blood pressure:76.20-90.79 mmHg) are beneficial for improvement of neurological function.