A backfire proof nozzle distributor for high temperature gas fluidized bed furnace was designed and developed. The specially designed structure allows gas and air to mix well during jetting process. The distributor can work at low gas pressure and the back-flow slots in it prevent particles from flowing back into the plenum chambers and tubes. The fluidization and combustion of a gas fluidized bed furnace with cross-section area of 350 x 350 mm(2) using the distributor were investigated for five kinds of spherical hollow Al2O3 particles belonging to Geldart Group B. Even fluidization and efficient combustion are obtained. The backfire of gas fluidized bed furnaces often occurs with the premixing of air and gas after long time operation at high temperature is prevented completely. (C) 2004 Elsevier B.V. All rights reserved.