Choline (commonly in the form of Choline chloride) is one of the B categories of vitamin. It is acetylcholine in the biological organization. It is the components of lecithin and nerve acid fat. It is used by most animals as a precursor of acetyl choline, which influences the transmission of impulses from nerves to muscles. It is also used as a source of methyl groups. In feed, the content of natural choline chloride is limited. It can not satisfy complete demand for the animal growing. Therefore, choline chloride is widely used as feed additive at home and abroad. It will stimulate the animal or poultry's growth, put on their weight rapidly and boost up the body's immunity function. It has prominence effects on improving the quality and quantity of eggs and meat. On the contrary, shortage of choline may cause liver diseases, retarded growth, perosis, reduced egg-laying rate and increased mortality.