Inorganic salt is an essential nutrition for human and animal. They are mostly in the combination form when in food, and often dissociated into inorganic salt ions in the body fluid. There are also a small amount of inorganic salts in the body fluid combined with protein, especially trace elements. According to their difference in electrical charge, inorganic salts can be divided into cations and anions. Na +, K +, Ca2 +, Mg2 +, Cl-, HCO3-, HPO42- are the main inorganic salts due to their large content while Fe2 +, Fe3 +, Cu +, Cu2 +, Mn2 +, Mn4 +, CO2 +, Cr3 +, Cr6 +, Cd2 +, Zn2 +, Br - I- are called trace elements for their trace amounts in the body.