Atrial　Fibrillation　is　the　most　common　sustained　cardiac　arrhythmia.　Minimally　invasive　ablation　using　surgical　navigation　technology　gradually　becomes　the　main-stream　method　in　atrial　fibrillation　surgery.　In　this　paper,　a　simplified　3D　antenna-myocardium-blood　numerical　model　is　built　and　specific　absorption　rate　(SAR)　distribution　is　investigated　at　the　frequency　of　2450MHz　using　the　FEM　method　embodied　in　Ansoft　HFSS.　The　peak　SAR　is　localized　in　the　tissue　at　about　26mm　along　the　axis　of　microwave　antenna　(with　antenna　length　about　30mm)　and　very　low　SAR　values　is　along　the　antenna　length.　The　electromagnetic　numerical　results　validated　that　the　microwave　antenna　can　deliver　localized　microwave　power　and　provide　acceptable　SAR　pattern.　Also　the　research　does　an　initial　coupled　electromagnetic-thermal　analysis　to　obtain　the　temperature　distribution　with　increasing　heating　time　during　microwave　ablation.　©　2012　IEEE.