Abstract:The aluminum nitrate and sodium aluminate solution were used as mainly raw materials, after adding some additive, aluminum hydroxide seed crystal was prepared in the method of neutralization. The sub-micron aluminum hydroxide was prepared by precipitation after the seed crystal was added to sodium aluminate solution. When the additive was acetic acid, the neutralization temperature was 60℃, the stir-ring speed was 400r/min, and the beginning temperature of precipitation was 60℃, the final temperature was 55℃, the total precipitation time were 48 hours, the dosage of seed crystal were 2-3%, the sub-micron aluminum hydroxide with narrow particle size distribution(D50 is about 1.8μm, D90＜3.5μm) , suitable BET(BET＜5.0m2/g) and completely morphology was prepared. Compared with the EVA retardant alu-minum hydroxide from foreign country, the particle size distribution, BET, oil absorption and morphology of both products were similar. So the aluminum hydroxide prepared in test had a chance to replace the for-eign products.