This study discussed the performance test of a 20ton steam/hr industrial fluidized bed combustor which was designed and installed at the site of Dong Chang paper company by Hyundai Heavy Industry(HHI) and Korea Institute of Energy and Resources(KIER). The operating conditions of the boiler, the properties analyses of solids and fuel, combustion efficiency, thermal efficiency, the emission of flue gas, load control and the erosion of heat transfer tube were measured and discussed.