New classification of diabetes mellitus was proposed by ADA international committee on the diagnosis and classification and by WHO consultation committee. The classification based on the pathogeneses of diabetes and also on the stages of diseases. Since our knowledge on causes of diabetic syndrome is not yet enough to classify diabetes in genetic bases, the classification had been carried out some sort of mixture of pathogeneses, genetic findings and clinical features of hyperglycemia. Stages of diseases based on the natural course of diabetes mellitus in reference to shortage of insulin effects and degree of chronic hyperglycemia. These two components of classification composed two dimensions of the field that expresses all the pathogeneses and metabolic conditions of all diabetic patients.