This　paper　presented　numerical　analysis　for　microwave　ablation　therapy　with　a　water-cooled　antenna　operating　at　60W　in　the　vitro.　An　axis　symmetric　finite　element　model　was　developed　to　simulate　the　temperature　field,　in　which　the　influences　of　the　water　flow　and　heating　time　on　the　temperature　distribution　were　investigated.　Results　show　that　the　effect　of　water　flow　rate　nearly　made　no　difference　on　the　ablation　size　under　the　three　given　water　velocity　and　heating　time　can　affect　the　ablation　area　evidently.