Abstract: Superfine magnesium hydroxide was prepared by homogeneous precipitation method with magnesium chloride and sodium hydroxide as raw materials.Influence of different dispersants on product yield and particle size，and the influence of different dispersants，magnesium chloride concentration，and temperature etc.on settlement rate of magnesium hydroxide were investigated.Meanwhile the product particle sizes and yields were compared while the water and ethanol were selected as the reaction media respectively.Results showed that when the glucose as dispersant and under the conditions of 0.75 mol/L magnesium chloride concentration，and 60 ℃ reaction temperature，magnesium hydroxide production rate was high，and the particle size was small （about 6.4 μm） with more uniform distribution.              

Key words: magnesium hydroxide；settlement rate, superfine, homogeneous precipitation method