Abstract： Objective To evaluate the relationship between aged diabetes mellitus and cognitive impairment in community elders.Method 308 type Ⅱ diabetic patients, including 225 diabetes patients and 164 diabetes with hypertension patients, were random selected in our study. 225 hypertension and 186 healthy elders were random selected as controls. Mini-Mental State Examination (MMSE) was tested on each case. According to DSM-IV, all participants were classified into three groups ( normal, MCI and dementia) .Result MMSE scores in diabetes patients were lower than that in healthy controls(25. 87±3.33 vs 26. 86 ±2. 82, F = 9.62, P < 0. 01), and scores in diabetes with hypertension group (24. 68 ±4. 36 ) were much lower than that in healthy controls ( F =37. 16, P <0.01). Conclusion Senile diabetes were positive correlated with cognitive impairment. Diabetes were a risk factor of dementia in seniles. Diabetes with hypertension can increase cognitive impairment in community elders.