Abstract: 79 patients with an initial onset of ketosis or ketoacidosis were classified into four groups,based on the presence of islet autoantibodies(A+or A-) and-βcell functional reserve(β+or β-).According to their clinical characteristics,biochemical parameters and therapeutic consequences,the four groups can be considered as type 1 DM,idiopathic type 1 DM,latent autoimmune diabetes in adults(LADA) and type 2 DM respectively.