Abstract: Objective :To study the effect of cFLIP antisense oligodeoxynuclecotide on the apoptosis in human lung adenoma cell SPCA-1 induced by liposome and to discuss the selective blocking activity of antisense technique on gene expression. Methods :Antisense and nonsense oligodeoxynucle-cotides cFLIP were transformed into human lung adenoma cell SPCA-1 induced by liposome Lipofectamine P 2000. After transfection, MTT assay was used to detect cells growing condition. RT-PCR assay was used to observe the expression of cFLIP gene, Western Blot assay for the expression of cFLIP protein, and at the same time the in situ terminal mark (TUNEL) and flow cytometer for cellular apoptosis. Results : Cellular inhibition rate went up to 71.52％ in antisense oligodeoxynuclecotide group higher than those in nonsense oligodeoxynuclecotide group and liposome controls in MTT assay. Twenty four hours after transfection, cFLIP gene expression in antisense oligodeoxynuclecotide group was less than that in control group (P<0.01) in RT-PCR assay. cFLIPL and cFLIPS protein expression decreased in Western Blot.In TUNEL assay, nuclear positive staining was observed. In flow cytometer test, the peak marking apoptosis was observed. Conclusions : The expression of cFLIPL/S gene and protein are decreased remarkably in SPCA-1 cells after transfection of cFLIP antisense oligodeoxynuclecotide, through which cFLIPL/S mRNA may induce tumoral cells into apoptosis.