Abstract: Objective To investigate the effects of the serum from burned patients(burn serum) on inhibitor of κBα(IκBα) degradation and nuclear factor-κB(NF-κB) activation in the endothelial cells in order to explore the role of burn serum on endothelium activation. Methods Cultured endothelial cells(ECV-304) were stimulated by the serum from healthy volunteers, burn serum and burn serum with pyrrolidine dithiocarbamate(PDTC), respectively. Activation of endothelial NF-κB at 30, 60, 120, 240 min after stimulation was tested by electrophoretic mobility shift assay(EMSA) and the degradation of endothelial IκBα at these time points determined by Western blotting. Results Compared with that in the control group, cytosolic IκBα degradation in the endothelial cells occurred within 30 min after burn serum stimulation, and peaked at 60 min, followed by gradual recovery in the cytoplasm till reaching the pre-stimulation level at 2 h. Meanwhile, the activity of endothelial NF-κB was markedly increased, reaching the peak at 30 to 60 min with subsequent gradual decrease 2 h after stimulation. PDTC could effectively inhibit endothelial IκBα degradation and activation of NF-κB induced by the burn serum. Conclusion Burn serum might induce the degradation of IκBα to activate NF-κB, which ultimately leads to cytokine release from the endothelium.