Aim To investigate the effect of cigarette smoke extracts (CSE) on protein S-nitrosylation in human umbilical vein endothelial cells (HUVEC). Methods The experiments performed in HUVEC. The levels of protein S-nitrosylation were analyzed by using immunofluorescence, and further confirmed by biotin switch method. Protein expression was analysed by Western blot. In addition, superoxide anion were also detected during the experiment. Results CSE (0.005%, 0.01%, 0.02% and 0.04%) reduced the levels of protein S-nitrosylation in dose-dependent manner.Sodium nitroprusside (SNP), nitrosoglutathione (GSNO), NONOate and apocnin restored the reduction of protein S-nitrosyation induced by CSE. Moreover, CSE increased levels of superoxide anion, which were inhibited by apocnin. Conclusion In HUVEC, CSE is able to reduce the protein S-nitrosylation level, which is associated with superoxide anion accumulation and nitric oxide (NO) pathway blockage.