Granulation experiment was carried out in a 0.109m ID, 1.8m height fluidized bed combustor of the multi-sized particles. Granulation of fine coal particles and fluidizing characteristics were investigated by the pressure fluctuations, combustion efficiency, temperature profile and mean particle diameter. Granula-tion mechanism was studied by the SEM analysis. Defluidization occurred in the mixed firing of salt and anthracite coal and the information on the information on the defluidization phenomena was interpreted with the pressure fluc-tuation signals and temperature profile. It was found that the combustion efficiency in the elutriated stream was increased 3-4 times by the granulation of fine coal particles and that the granulation mechanism was agglomeration model.