A new combustion control system for a fluidized bed incinerator being fed with unshredded municipal solid wastes (MSW) was developed and tested under the control of primary and secondary air flow rate, and the feeder speed. This control system corresponds to the detection of brightness in a furnace and is for the purpose of obtaining stable combustion; also, this method could cope with recent stringent air pollution regulations. As a result,the combustion was stabilized and the concentration of carbon monoxide in the waste gas become less than 10 ppm, whereas it was sometimes about 1000 ppm in the case of no new combustion control system. In addition, a new method of the feed forward control that weakens the fluidization of sand before MSW reaches the fluidizing sand by detecting the MSW feed rate is raised; this method will be very effective for combustion.