Aim To investigate the effect of ACEI and ARB on the transcription factor NF-κB activation in monocytes induced by lipopolysaccharide (LPS). Methods Monocytes from normal deliveried female umbilical veins were incubated with bacterial LPS in presence or absence of different ACE inhibitors or angiotensin Ⅱ AT1 antagonists. At the end of incubation,the cells were harvested by trypsin digestion method. In order to evaluate a possible contribution of ACEI and ARB on NF-κB activation induced by LPS, we used western blotting to study phosphorylation and degradation of inhibitor protein IκBαin the cytoplasmic,the translocation of p65 subunits to the nucleus at different times. Results The data showed that LPS-dependent phosphorylation and degradation of IκBα was markedly impaired in ACEI and ARB-treated monocytes and the translocation of p65 subunit to the nucleus was inhibited at the same time. Conclusions ACEI and ARB has inhibitory effect on the transcription NF-κB activation in monocytes.