Simultaneous removal of SO, and NO from simulated gas was investigated using a continuously operating fluidized bed reactor with variables of gas velocity, sorbent/catalyst feeding rate, aspect ratio (L/ D), temperature, sorbent/catalyst size. NMO (natural manganese ore) was used as a sorbent and catalyst trf size from 0.715 mm to 0.194 mm in diameter. Particle size, aspect ratio, and sorbent feeding rate did not affect the reduction of NOx with ammonia, and NO removal efficiency was about 94% at 350 degreesC, gas.' velocity of 0.204 m/sec, L/D = 1.0, SO removal efficiency was affected by temperature, gas velocity, sorbent/catalyst feeding rate, aspect ratio and sorbent/catalyst size and it was about 92% at 450 degreesC, gas velocity of 0.204 m/sec, sorbent/catalyst feeding rate of 8.54 g/min, L/D = 1.0.