Abstract: Fulminant type 1 diabetes mellitus(FT1DM)is a new subtype of type 1 diabetes.It is characterized by rapid occurrence of extreme hyperglycemia or diabetic ketoacidosis,generally less than 2 weeks,with glycosylated HbA1c<8.7%.Genetic factors,virus infection,antiviral immune mechanism and immunomodulatory factors are all related to the development of FT1DM,certain drugs and pregnancy are high-risk factors for it.This article reviews the research progress on the etiology of FT1DM.