摘要Objective To report 21 cases of postinfectious encephatitis according to ICD-NA, postinfectious/parainfectious encephalitis is an independent disease.Methods Using the uniform criteria provided by The Council of State and Territorial Epidemiologists (CSTE) and Centers for Disease Control and Prevention (CDC), we diagnosed postinfectious encephalitis among patients admitted to The First Hospital of Harbin Medical University and analyzed the characteristics of these cases. Results All the patients had histories of preceding infection, and most of them suffered from mental and conscious disorders. Adrenocortical hormone was effective.Conclusions Postinfectious encephalitis is an independent disease. According to this article, about 10% patients with encephalitis admitted to our hospital are postinfectious.