The relations between their electrocardiographic findings and their age, sex, ophthalmoscopic findings and blood pressure were studied on 531 persons in Okayama Prefecture, and the follwing results were obtained: 1. Abnormal electrocardiograms inceased with their age, blood pressure and the aggravation of ophthalmoscopic findings. 2. Arthmias such as premature beat and myocardidial infarction were more frequent with hypertensives and those of advanced age. Bundle branch block and auricularfibrillation were also frequent with those of advanced age. 3. As for the change of P wave, left auricolar hypertrophy was more frequent with those of advanced age. 4. Both in relation to their blood pressure and age, the left type with horizontal position of the electrical sxis predominated. This position was especially large in number with women beiween 40-60 years probably because of their physique. 5. Left ventricular hypertrophy and myocardial injury increased with the elevation of blood pressure, age and the aggravation of ophthalmoscopic findings. 6. It seems that the electrocardiograms of the aged persons were affected by such factors as their age and the blood pressure which had been rising previously.