Thedynamic　behavior　of　the　thermal　transport　characteristics　in　the　active　region　of　AlGaN/GaN　transistors　was　investigated　experimentally.　The　transient　temperature　rise,　the　sectional　temperature　distribution,　and　the　heat　transport　characteristics　were　all　measured　using　the　Schottky　gate　junction　voltage　characteristics　method.　The　results　show　that　three　steps　were　observed　in　the　transient　temperaturerise　and/or　Schottkygate　voltage　drop　curves.　The　transient　temperature　rise　behavior　at　different　positions　in　the　active　region　under　various　power　conditions　is　discussed　in　detail.　In　addition,　the　heat　transport　delay　in　the　active　region　of　the　AlGaN/GaN　transistors　is　also　studied.　The　results　indicated　that　the　transport　velocity　of　the　heat　is　1.47　m/s.　This　is　important　when　changes　occur　to　the　electrical　characteristic　parameters　of　the　device,　because　any　heat　transport-related　delay　would　also　induce　associated　delays　in　the　changes　to　the　electrical　characteristic　parameters　in　the　AlGaN/GaN　transistors.