Aims: To explore memory impairment type 2 diabetes patients. Methods: 90 patients (aged from 30 to 85) and 90 controls with comparable age and education participated in the study. Four cognitive tasks, recognition of meaningless figures, digital symbol substitute, action memory (Subject performed task) and mental arithmetic (digital span), were administered. Results: a special age effect was identified in memory impairment of NIDDM patients compared with those of controls. Furthermore, action memory experiments show an experimental dissociation, that both free recall of well-integrated items with enactment support and poor-integrated items without enactment were affected by NIDDM in patients aged form 30 to 70.Conclusions: Cognitive impairments in NIDDM patients were associated with both normal aging and impaired memory function.