In　order　to　improve　the　accuracy　of　near-field　forecasting　temperature　during　microwave　hyperthermia,　this　paper　analyses　the　rising　curve　of　the　temperature　in　near-field,　and　studies　the　effect　of　water　vaporization.　The　enthalpy　of　liver　issues　and　high-temperature　SAR　are　calculated　and　introduced　to　simulation　process.　The　results　show　that　the　accuracy　of　near-field　temperature　in　simulation　is　improved.