Supercritical　water　fluidized　bed　is　a　new　reactor　concept　for　biomass　gasification.　In　this　paper,　an　experimental　study　on　the　hydrodynamics　of　a　supercritical　water　fluidized　bed　was　conducted.　The　frictional　pressure　drops　of　a　fixed　bed　and　a　fluidized　bed　were　measured　for　a　temperature　ranging　from　633　to　693　K　and　pressure　ranging　from　23　to　27　MPa.　The　results　show　that　the　Ergun　formula　for　calculating　the　frictional　pressure　drop　of　a　fixed　bed　can　still　be　applied　in　supercritical　water　conditions.　The　average　deviation　between　Ergun　formula　and　experiment　results　is　13.3%.　A　predicting　correlation　for　the　minimum　fluidization　velocity　in　a　supercritical　water　fluidized　bed　was　obtained　based　on　the　experimental　results　of　a　fixed　bed　and　the　fluidized　bed　pressure　drop.　The　average　error　between　the　correlation　and　experiment　results　was　about　3.1%.　The　results　in　this　paper　are　useful　for　the　design　of　SCW　fluidized　bed.　(C)　2012　Elsevier　Ltd.　All　rights　reserved.