The aim of study was to explore the effects of NF-kappaB inhibitor Bay 11 - 7082 on Fas/FasL system and Fas-mediated apoptosis in HL-60 cells. The mRNA and protein expression levels of Fas, FasL and XIAP after treatment with Bay 11 - 7082 were detected by RT-PCR and FCM respectively. The level of sFasL was detected by ELISA before and after treatment with Bay 11 - 7082; apoptosis was detected by FCM before and after treatment with Bay 11 - 7082. The results showed that after treating HL-60 cells with Bay 11 - 7082, the mRNA and protein levels of FasL and XIAP were lower than that of controls, the difference was significant by statistic analysis (p < 0.05). Neither the mRNA and protein levels of Fas, nor the level of sFasL changed significantly (p > 0.05). Apoptotic rate of HL-60 cells treated with Bay 11 - 7082 was significantly higher as compared with controls (p < 0.05). It is concluded that Bay 11 - 7082 can enhance Fas-mediated apoptosis in HL-60 cells by down-regulation of FasL and XIAP levels.