In recent years, more and more previously thought to be unknown encephalitis was found to be a specific antigen associated encephalitis，but because of the lack of recognition in the clinic, usually been misdiagnosed as other causes of encephalitis. Therefore, it is urgent to establish a database of autoimmune encephalitis in Chinese population. The prospective clinical trial of atutoimmune encephalitis in China, by screening the autoimmune encephalitis associated antibody and summarizing the cases analysis, in order to provide evidence for clinical diagnosis and treatment of autoimmune encephalitis.