Potassium sorbate has been as the prime preferable food preservatives because of its excellent preservatives and high safety, it is one kind of nonsuturated fatty acid compounds, and can be absorbed by human body rapidly, then decomposed into CO2 and H2O, moreover no remaining in body. Potassium sorbate can restrain effectively the activity of mould, yeast and aerophile bacteria. Restrain growth and reproduction of the pernicious micro oraganism as pseudomonas, staphylococcus salmonella action to restrain growth is more powerful than killing. Meanwhile, it can not restrain useful microoraganim growth as Anaerobic spore-bearing bacilli, acidophil therefore to lengthen food store period and remain food original flavor. The preservative efficiency of potassium sorbate is 5-10 times sodium benzoate. Color less crystals of a white crystalline powder Freely soluble in water, sparingly soluble in ethanol. It is unstable if not sealed well, will be oxidized into colored ones and absorbing moistures in case in air for long time. Application.: Potassium sorbate is used to inhibit molds and yeasts in many foods, such as cheese, wine, yogurt, dried meats, apple cider and baked goods. Potassium sorbate has been used extensively in drink, vegetables in soy, tobacco, drugs, cosmetics, agriculturals products, forage and other domain.