Microwave　ablation　(MWA)　is　a　minimal　invasive　operation　for　treating　lung　cancer,　and　it　has　been　widely　used　in　clinic.　Lung　contain　tracheas　and　bronchus,　and　the　properties　of　thermal　conductivity,　electrical　conductivity　and　density　change　by　variations　in　the　lung＇s　internal　air　volume.　Thus,　it　is　difficult　to　control　the　precise　formation　of　coagulation　zones.　In　this　paper,　we　propose　to　use　finite　element　method　(FEM)　to　simulate　the　microwave　ablation　for　lung　cancer　in　a　simple　lung　model.　We　set　the　power　as　10　watts　for　10　s　at　2.45　GHz.　We　built　the　lung　model　and　a　small　bronchus　was　placed　close　to　the　opened-tip　coaxial　antenna　with　airflow　at　the　rate　of　3　L/min.　We　operated　eight　patterns　including　the　collapsed　and　aerated　lung　in　different　thermal　conductivity,　electrical　conductivity　and　density　to　simulate.　The　results　preliminarily　showed　that　the　electrical　conductivity　had　the　greatest　influence　on　the　microwave　ablation　temperature　field　of　lung.