Whether inhibiting the activity of nuclear factor(NF)-κB potentiates cisplatin-induced apoptosis in non-small cell lung cell line A549 cells was investigated.The recombinant plasmid pcDNA3.1(+)/IκBα expressing IκBα was constructed.The in vitro cultured A549 cells were transfected with pcDNA3.1(+)/IκBα alone,or pcDNA3.1(+)/IκBα combined with cisplatin.The mito-chondrial membrane potential(?ψm) was determined by rhodamine 123,the activity of caspase-3 was tested by colorimetric assay,and cell apoptosis was detected by flow cytometry with the annexin Ⅴ/propidium iodide assay.The results showed that the activity of NF-κΒ in A549 cells was inhibited by transfecting pcDNA3.1(+)/IκΒα.Transfection of pcDNA3.1(+)/IκΒα alone did not promote apoptosis.Treatment of cisplatin alone had a little effect on cell apoptosis.Transfection of pcDNA3.1(+)/IκΒα combined with cisplatin treatment significantly induced apoptosis of A549 cells.It was concluded that inhibiting the activity of NF-κB potentiated cisplatin-induced apoptosis of A549 cells. Whether Inhibitory activity of nuclear factor (NF) -κB potentiates cisplatin-induced apoptosis in non-small cell lung cell line A549 cells was infected.The recombinant plasmid pcDNA3.1 (+) / IκBα expressing IκBαwas constructed.The in vitro cultured A549 cells were transfected with pcDNA3.1 (+) / IκBα alone, or pcDNA3.1 (+) / IκBα combined with cisplatin. The mito-chondrial membrane potential (ψψ) was determined by rhodamine 123, the activity of caspase-3 was tested by colorimetric assay, and cell apoptosis was detected by flow cytometry with the annexin Ⅴ / propidium iodide assay. The results showed that the activity of NF-κΒ in A549 cells was inhibited by transfecting pcDNA3.1 (+) / IκΒα.Transfection of pcDNA3.1 (+) / IκBα alone did not promote apoptosis. Treatment of cisplatin alone had a little effect on cell apoptosis. Transfection of pcDNA3.1 (+) / IκBα combined with cisplatin treatment significantly induced apoptosis of A549 cells .It was concluded that inhibiting the activity of NF-κB potentiated cisplatin-induced apoptosis of A549 cells.