Aim The present studies often on type 2 diabetes mellitus and AD related research, this paper is to evaluate the cognitive function of the patients with type 2 diabetes who did not complain about cognitive symptoms, and to further explore the levels of glucose, insulin, glycosylated hemoglobin and mental status of type 2 diabetes mellitus (T2D) with and without mild cognitive impairment (MCI).MCI is a syndrome defined as the presence of significant cognitive decline that does not notably interfere with social or occupational function and is thought to be dementia clinically identifiable.