3D　visualization　of　hepatic　tumor　is　a　key　technique　in　preoperative　planning　system　of　microwave　hepatic　tumor　ablation,　whose　performance　determines　the　reliability　and　effect　of　surgical　planning　result.　In　this　paper,　a　new　method　for　3D　visualization　of　hepatic　tumor　was　proposed.　Firstly,　a　segmentation　method　based　on　graph-theory　was　applied　to　automatically　extract　hepatic　tumor.　Secondly,　a　new　marching　cubes　algorithm　was　employed　to　reconstruct　tumor　surface.　Finally,　surface　rendering　and　displaying　were　accomplished　by　3D　graphic　library　OpenGL.　The　proposed　method　was　evaluated　via　CT　images　of　6　patients　suffering　from　hepatic　carcinoma.　The　results　showed　that　the　3D　reconstruction　was　fast　and　the　visualization　of　the　tumor　model　was　satisfying　without　manual　intervention.