Objectives : We studied Effect of Platycodon grandiflorum on Lung carcinoma Methods : By using cDNA microarray technique, we analyzed the effects of AEPG(aqueous extract of Platycodon grandiflorum) on the gene expression profile. Results : Out of 384 genes screened associated with growth inhibition of carcinoma cell, 9 genes were founded to be affected in their expression levels by more than 1.2-fold after treatment with AEPG. And 67 genes were changed the expression level 0.5 times more than that of reference RNA after treatment of AEPG. Conclusions: These findings suggest that P. grandiflorum has strong potential for development as an agent for prevention and treatment against human lung cancer.