Potassium aluminum sulfate is an inorganic substance and chemical formula is KAl(SO4)2. It is a colorless crystal or powder. Potassium aluminum have no smell, slightly sweet and astringent taste with convergence. It will lost crystal water in the dry air weathering and will dissolved water in the humid air. It is easily soluble in glycerol and soluble in water. Its aqueous solution will occur acidic reaction. After hydrolysis, it will have aluminum hydroxide gelatinous precipitate. Potassium aluminum is insoluble in alcohol and acetone. 9 molecules of water are lost when sulfuric acid is dried at 60 ~ 65℃, and 12 crystals are completely lost at 200℃. Sulfur trioxide is decomposed at higher temperature.