Abstract： Objective To investigate clinical characteristics of cerebral blood perfusion in patients with T2DM and T2DM accompanied with hypertension.A part of the patients were studied on the metabolism of cerebral galactoside. Methods 99mTc-ECD was injected into 77 patients diagnosed as T2DM,and SPECT imaging of the cerebral cortex was done. And also 18 F-FDG imaging of the cerebral cortex was done in twelve of them. Results In T2DM patient the radioactivity was decreased in the temporal lobes of the cerebral cortex. Conclusion Our investigation demonstrates that although some older T2DM patients do not suffer from brain vascular accidents, all of them have a decreased cerebral blood perfusion and decreased cerebral metabolism. The early checked cerebral blood perfusion and metabolism may be important for these patients.