【Abstract】 In the water-in-oil mieroemulsion system of Triton X-100, 1-hexanol, cyclohexane and Fe（NO₃）₃ aqueous solution, α－Fe₂O₃ ultrafine particles were prepared by the method of precipitation using NH₃. From transndssion electron ndcrographs the mean dianreter of particles is about 3nm. The trifornlity of particle is good. These result have been confirmed by the method of Mossbauer spectrum measurement. The conditions of preparation of α－Fe₂O₃ ultrallne particles could be controlled easily and the reaction medium could be used cyclically.更多还原