Abstract: In a simple experimental condition without dustproof equipment, satisfactory spherical magnetite particles of narrow size distribution had been obtained by aging ferrous hydroxid gels in the presence of nitrate ion. this note reports a new result according to the modified experimental procedure, in which included the mixed of reactants, elimination of oxygen and magnetic separation etc. According to transmis-sion electron micrographs the mean diameter of particles is about 0.5 μm.