Usnic acid is a secondary metabolite in lichens whose role has not been completely elucidated. Lichen extracts containing usnic acid have been utilized in medicine, perfumery, cosmetics, and ecology. Usnic asit inhibits cell growth, induces the cell cycle arrest and apoptosis in human lung carcinoma. Methods:Herein we analyzed the antitumoral effect of usnic acid on the same cell line. We analyzed the gene expression results on APOPT1, CYCS, APAF1, CASP3/9, TNF, BCL2, BCL2L1 and AIFM1 genes which have possible role on cell apopitosis. Results: Usnic acid has stimulatory effect on APOPT1, CYCS, APAF1, CASP3, CASP9 gene expressions in our experiments. Conclusion: Usnic acid has antitumoral effect on cancer cells, affecting on mithocondrial apopitotic genes.