Western blot and Real-time PCR were used to detect the expression level of MTA3 after transfection in non-small cell lung cancer (NSCLC) cells A549 and H157.Apoptosis analysis was used to detect the change of cell apoptosis with upregulated/downregulated of MTA3, and Western blot was used to detect the the expression of the protein related with apoptosis, while downregulate the expression of MTA3 in NSCLC cells A549 and H157. The gene discussed is MTA3; the disease is non-small cell lung carcinoma.