The discovery of prion broke the traditional idea that "virus must have nucleic acid", so it is of great significance in theory. (Pr)prpst (-m) Human prion diseases include: Kuru disease, Gerstmdann syndrome, GSS), Creutzfeldt-Jakob disease (JD), new variant CJD or human mad cow disease and fatal familial insomnia. Prion diseases of animals include: bovine spongiform encephalopathy, commonly known as mad cow disease; Sheep itch; Mink infectious encephalopathy and cat spongiform encephalopathy. The typical symptoms of this kind of diseases are dementia, loss of coordination and nervous system disorder, and the main lesion is amyloidosis in protein. Such diseases are hereditary, contagious and sporadic.