Purpose:　The　aim　of　this　study　is　to　contrast　the　coupling　algorithm　(CEE)　and　boundary　heat　exchange　coefficients　(Nu)　used　in　treatment　of　the　large　blood　vessel　in　thermal　ablation.　Methods:　Based　on　the　Pennes　bioheat　transfer　equation,　the　models　with　blood　vessel　parallel　to　microwave　antenna　were　built　with　finite　element　method.　In　two　kind　of　simulation,　blood　flow　rate　was　set　in　0.2　m/s　or　boundary　heat　exchange　coefficients　was　set　in　1750　W　/　(m2　center　dot　degrees　C),　respectively.　Results　and　conclusions　:　There　was　no　significant　difference　on　shape　of　effective　ablation　areas　and　54　degrees　C　temperature　contours　by　using　two　kinds　of　simulation　methods,　especially　the　place　far　away　from　the　blood　vessel.　At　the　place　near　the　blood　vessel,　the　method　of　CEE　is　closer　to　real　condition　which　considers　directivity　of　blood.　What＇s　more,　there　are　higher　temperature　by　using　method　of　Nu　inside　effective　ablation　areas.