has the function of converting of some kinds of amino acids to gain the balance. Threonine has a hydroxyl in its structure, which retains water in human skin. Combining with the oligosaccharide chain, it plays an important role in protecting the cell membrane, and promotes in-vivo phospholipid synthesis and fatty acid oxidation. Its preparation has the medicinal function of enhancing human body development and resisting fatty liver, being a composition of the composite amino acid infusion. Meanwhile, threonine is the raw material to produce single-amide streptozotocina, an antibiotic with high efficiency and low allergenicity.