Abstract: The regeneration of large particle catalyst in FCC naphtha aromatization was studied in a fixed bed microreactor. CO2/CO mol ratio in product gas during the regeneration was analyzed and apparent kinetic equation for coke combustion was derived. The results showed that the cokeburning rate is in first order with respect to both carbon content and oxygen partial pressure. Because of the internal diffusion, the cokeburning rate for large particle catalyst is only about 60% of that for the small one. CO2/CO mol ratio decreases with the increase of regeneration temperature from 600℃ to 720℃; it increases greatly with the temperature when the regeneration temperature exceeds 720℃. The CO2/CO mol ratio increases linearly with the oxygen partial pressure.