To　study　the　effect　of　the　vessel　on　the　ablation　field,　the　temperature　field　near　the　blood　vessel　at　different　distances　from　the　antenna　and　different　blood　flow　rates　were　measured　in　vitro　experiments.　Using　infusion　tube　instead　of　hepatic　lartery,　and　setting　the　flow　rate　based　on　the　blood　flow　velocity　of　the　hepatic　artery,　copper-constantan　thermocouples　(TCs)　were　used　to　measure　the　temperature　near　the　blood　vessel　in　vitro　experiments,　which　were　compared　with　the　simulation　results　in　the　same　condition.　Experimental　results　showed　that　when　the　microwave　antenna　was　1.0　cm　away　from　the　vessel,　the　heating　pattern　was　not　symmetrical　about　the　antenna　because　the　heat　convective　of　blood,　and　large　temperature　gradient　existed　in　the　side　of　the　blood　vessel.　The　greater　the　blood　flow　was,　the　smaller　the　temperature　field　of　microwave　ablation　was.　When　the　antenna　was　1.5　cm　away　from　the　blood　vessel,　the　heating　pattern　was　more　circular,　and　the　temperature　contours　of　two　blood　flows　were　almost　overlapped.　When　the　antenna　was　2.0　cm　away　from　the　blood　vessel,　the　heating　pattern　was　circle,　and　almost　symmetrical　about　the　microwave　antenna.　When　the　blood　flow　increased　(from　22　cm/s　to　55　cm/s),　vessel　influence　on　the　temperature　field　increased　(the　temperature　difference　with　22　cm/s　up　to　10℃),　and　temperature　fields　further　reduced.　The　effect　of　blood　on　the　temperature　field　could　be　ignored　if　the　distance　between　blood　vessel　and　the　microwave　antenna　exceeded　2.0　cm.　When　the　distance　was　less　than　2.0　cm　and　the　blood　velocity　was　more　than　22　cm/s,　in　order　not　to　affect　the　efficacy　of　the　ablation,　blood　vessel　blocking　was　suggested　to　implement.　©,　2014,　Beijing　University　of　Technology.　All　right　reserved.