The　Eulerian　two-fluid　model　based　on　Kinetic　Theory　of　Granular　Flow　in　a　fluidized　bed　was　established　in　this　paper,　and　the　physical　model　of　movement　of　single　bubble　along　the　wall　is　adopted.　The　comparison　studies　of　particle　distribution,　temperature　distribution　and　transient　heat　transfer　characteristics　between　supercritical　water　(SCW)　fluidized　bed　and　gas-solid　fluidized　bed　were　carried　out.　The　results　show　that　the　bubble　diameter　and　rise　velocity　in　SCW　fluidized　bed　is　smaller　than　those　in　gas-solid　fluidized　bed.　The　bed-wall　heat　transfer　coefficient　is　negative　related　to　solid　volume　fraction　in　SCW　fluidized　bed,　while　positive　in　gas-solid　fluidized　bed.　What　is　more,　the　bed-wall　heat　transfer　coefficient　is　sensitive　to　superficial　velocity　where　the　solid　volume　fraction　is　low,　which　is　different　from　gas-solid　fluidized　bed.