The recycling of ceria-based glass polishing powder by alkali treatment was investigated. Major impurities in the waste, a SiO2 component from fine glass powder and an Al2O3 component from coagulating agents, could be removed easily at 50-60 degrees C in a 4 mol kg(-1) NaOH solution within 1 h. These impurities react with NaOH to precipitate as zeolite at higher temperature. Thus, it is expected that a recycling process which can regenerate polishing powder and convert SiO2 and Al2O3 components into zeolite can be designed.