Incineration experiments are carried out to obtain the fundamental data for application of a two-stage swirl-flow fluidized bed combustor to the incineration of paper sludge wastes with high moisture content. Experimen-tal parameters are identified as the fluidizing air velocity, fuel feed ratem, bed temperature and stoichiometric air ratio. Experimental results show that temperature distribution within the fluidized bed is not uniform due to the segre-gation by density difference between bed materials and paper sludge. A part of unburnt fines entrained from the lower bed are separated from the gas stream due to the swirling effect in the upper stage freedboard of the combustor, and eventually settled down on the upper bed and burnt by secondary air. Further, the non-separated remainder has a long residence time as it moves along the swirling flow. Therefor, the combustion efficiency of paper sludge in the two-stage swirl-flow fluidized bed combustor is enhanced compared with that in the single-stage fluidized bed combustor under the same operating conditions.