Purpose:　To　propose　an　improved　specific　absorption　rate　(SAR)　computation　method　by　incorporating　a　thermal　conductivity　item,　develop　mathematical　simulation　models　based　on　the　SAR,　and　enhance　the　accuracy　of　temperature　simulation　for　2450-MHz　microwave　fields.　Materials　and　methods:　Experimental　data　of　2450-MHz　microwave　antenna　were　obtained　with　a　phantom　and　then　new　SAR　equations　were　calculated　according　to　Pennes　bio-heat　transfer　equation.　Next,　the　SAR　equations　were　regarded　as　heating　sources　and　SAR-derived　temperature　changes　were　simulated　numerically;　Finally,　temperature　measurement　results　were　compared　with　simulation　data　to　validate　the　accuracy　of　the　new　SAR　method.　Results:　The　simulated　and　measured　temperature　changes　were　generally　in　good　agreement　for　the　phantom.　According　to　comparison　results,　the　maximum　error　was　less　than　6　degrees　C,　the　average　error　was　less　than　2　degrees　C,　and　the　standard　deviation　was　less　than　1　degrees　C.　Conclusions:　This　new　SAR-derived　simulation　method　can　significantly　simplify　the　simulation　process　and　improve　the　prediction　accuracy　of　microwave　ablation　temperature　field.