Objective To investigate the correlation between blood pressure（ BP） in 24 hours after intravenous thrombolysis and early neurological deterioration in patients with acute ischemic stroke（ AIS）. Methods A total of 353 AIS patients admitted to Xuanwu Hospital Capital Medical University from November 1st， 2018 to September 30th， 2019 were enrolled by continuous and convenience sampling method. Logistic regression analysis was used to analyze the relationship between the blood pressure at admission， immediately after thrombolysis， in 24 hours， at daytime and nighttime after controlling confounding factors and the occurrence of early neurological deterioration. Results After adjusting for confounding factors， systolic blood pressure（ SBP） at admission（ OR=5.018， 95%CI：1.183-21.282，P=0.029）， diastolic blood pressure （DBP） at admission（ OR=4.691， 95%CI：1.106-19.886，P=0.036）， SBP at immediate time upon completion of thrombolysis（ OR=4.851， 95%CI：1.137-20.695，P=0.033）， DBP at immediate time upon completion of thrombolysis（ OR=4.918， 95%CI：1.158-20.885，P=0.031） and 24 hour average SBP（ OR=1.021， 95%CI： 1.002-1.040，P=0.033） were the risks affecting neurological deterioration. Conclusions BP during intravenous thrombolysis in AIS patients was independently associated with the occurrence of early neurological function deterioration.