Abstract: Objective To investigate the effect of angiotension II (AngII) on the activation of NLRP3 inflammasome and the expression of interleukin-1β (IL-1β) in human umbilical vein endothelial cells (HUVECs). Methods HUVECs cultured in vitro were treated with different concentrations of AngII for varying lengths of time to determine the optimal concentration and time for AngII exposure. To test the impact of different agents on the effect of AngII exposure, HUVECs were pretreated with AngII receptor blocker losartan, NAD(P)H inhibitor DPI and H2O2 scavenger CAT, caspase 1 inhibitor YVAD, or NLRP3 siRNA for silencing NLRP3, and the protein levels of NOX4, NLRP3, caspase-1 and IL-1β in HUVECs were analyzed by Western blotting. Results AngII treatment at the optimal concentration (10-9 mol/L) for 12 h significantly increased the protein levels of NOX4, NLRP3, caspase1 and IL-1β in HUVECs. Pretreatment with losartan, DPI, CAT, YVAD, or NLRP3 siRNA all attenuated the effects of AngII on the cells. Conclusion AngII can induce vascular inflammation by promoting the production of reactive oxygen species and activating NLRP3 inflammasome to increase the protein expression of IL-1β in HUVECs.