147 cases of diabetic patients complicated with cerebrovascular disease during the past two decades were analyzed. The prevalence of diabetes complicated with cerebrovascular disease was 18.6% in 791 admissions of diabetes mellitus and 9.8% in 1501 admissions of cerebrovascular diseases in the same period. 81 cases were males, and 66 cases were females. The mean age was 62 yrs (43-82). 131 of 147 cases (89.1%) were ischemic cerebrovascular accidents. The percentage is much higher than that in non-diabetics. All these cases were diabetes mellitus type Ⅱ. There was no relationship between the occurrence of diabetes complicated with cerebrovascular disease and the duration and the treatment of diabetes mellitus, but the severity and prognosis of diabetes complicated with cerebrovascular disease were related to the blood glucose level before and on the admission. The patients with blood glucos level more than 300 mg/dl were more severe and the mortality was high. Control of the blood glucose level in normal limits is important for the treatment and prevention of diabetes complicated with cerebrovascular disease.