To investigate the role of miR-33s in the inhibition of ATP-binding cassette transporter A1 (ABCA1) expression and cholesterol efflux induced by NF-κB, THP-1 macrophage-derived foam cells were treated with different concentrations of LPS to activate NF-κB with or without PDTC (NF-κB inhibitors)，the mRNA expression of miR-33s and its host gene SREBPs were detected by RT-PCR, the proteins expression of SREBPs were detected by Western blot, the binding capacifies of NF-κB p65 to SREBPs promoters were detected by chromatin immunoprecipitation. After cells were treated with LPS, miR-33s inhibitor or mimic were transfected, ABCA1 mRNA and protein were detected by RT-PCR and Western blot, respectively. The cholesterol efflux was detected by liquid scintillation counter. The results showed that expression of miR-33s and SREBPs were increased by NF-κB activation and decreased by adding PDTC. NF-κB p65 could directly combine with the SREBPs promoter. After transfected with miR-33s inhibitor, the inhibitory effect of NF-κB activation on ABCA1 expression was weakened, and cholesterol efflux was increased. On the contrary, the inhibitory effect on ABCA1 strengthened and cholesterol efflux decreased after transfected by miR-33s mimic. These results suggested that NF-κB activation could promote miR-33s expression, inhibit ABCA1 expression and cholesterol efflux.