As the first step of epidemiological studies of regional differences in apoplectic death rate, practical surveys were performed on hypertension and other cardiovas-cular disturbances in 4 regions with different apoplectic death rates in Akita Pre-fecture in order to find out factors concerned in the differences, and the following results were obtained. 1) Average blood pressure and frequency of hypertension were higher in the regions where apoplectic death rate was higher, but the former were not always lower where the latter was lower. There was no parallelism be-tween them. 2) As to the relation between frequencies of cardiovascular distur-bances in hypertensive subjects and apoplectic death rates in the 4 regions, fre-quency of electrocardiographic abnormality did not show any parallelism with the death rates but did with the frequency of funduscopic abnormality, especially of high degree and proteinuria. 3) The living environment in the region with high apoplectic death rate was unhygienic, and it is therefore considered that this may increase the danger of bacterial infection, producing as the result complication of nephrosis or arteriosclerosis, thus exacerbating hypertension.