Natamycin——nearby white or cream yellow crystal powder. It is a kind of odorless, tasteless, low dose and highly safe food antiseptics. It is slightly soluble in water, hardly soluble in most organic solvents. Its water solubility under indoor temperature is 30~100mg/L. When the pH is lower than 3 or higher than 9, the solubility will be increased, while the stability of natamycin will be decreased. As a kind of microbial preservation, natamycin receives much concern from people for its safe, natural, healthy characters. Natamycin is with many characteristics: prolongs food guarantee period, prevents deterioration caused by yeast and mould; reduces food recycling caused by deterioration, reduces production cost; satisfies the customers’ demand for natural food; not change the flavor of food; low dose, high efficiency; long antibacterial action time.