Povidone iodine is an unstable complex formed from the complexation of iodine with a surfactant, belonging to a type of topical iodine disinfectant. At room temperature, it is yellow-brown to red-brown amorphous powder which is soluble in water or ethanol but insoluble in ether or chloroform. Thevinyl-2-pyrrolidone homopolymer inside it is a kind of surfactants which can facilitate the wetting and penetration of solution on the object, thereby enhancing the sterilization effect of iodine. Of which 80 to 90% of the binding iodine can be depolymerization into free iodine with a large the concentration and a strong bactericidal capability. It is tasteless, non-irritating, non-allergenic, and of low toxicity. It is a kind of broad-spectrum fungicide which can kill viruses, bacteria, spores, fungi, and protozoa. At a concentration of 15ppm, within 1 minute, it can kill various kinds of bacteria (Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa) propagules; it takes a relative long time for it to kill Mycobacterium tuberculosis; killing fungi (B. subtilis) takes 1.5 hours; killing black variant of Bacillus cereus and Bacillus requires higher concentrations and longer time; at a concentration of 150ppm, within 10 minutes, it can destroy the hepatitis B surface antigen (HBsAg). In addition to be applied for the skin disinfection, this product can also be used for disinfecting of metallic medical equipment, utensils and the like. It is usually read or amber in the concentration for disinfection which can not only be directly applied to the skin or meninges of the surgical incision site of a patient, but also used for the in vitro flushing purposes in obstetrics and urology. When its concentration is reduced to below 10ppm, it turns white or pale yellow and loses bactericidal activity.