Mass examination was carried out in935individuals aged40to90yeas. Blood pressure was measured and electrocardiograms recorded in all cases. Blood was sampled for the determination of serum total cholesterol, and urine for the determination of albumin and sugar. The results can be summarized as follows: 1) Systolic blood pressure of 150 to 199 mmHg was found in90% in the5th decade, 25% in the 6th decade, 41% in the 7th decade, 44% in the 8th decade and 39% in the9th decade. Systolic blood pressure higher than 200 mmHg was found in 2% in the5th decade, 4% in the 6th decade, 6% in the 7th decade, 18% in the 8th decade and 29% in the 9th decade. 2) Coronary insufficiency was divided into3grades: an upstroke of the ST-T segment is more horizontal than normal with an exaggerated U wave in mild coronary insufficiency, the ST segment is depressed with a biphasic T wave in moderate coronary insufficientcy, and the ST segment is more depressed with a negative T wave in marked coronary insufficiency. Moderate-coronary insufficiency was found in 4.2% in 5th decade, 18.7% in the 6th decade, 19.9% in the 7th decade, 14.9% in the 8th decade and 19.2% in the9th decade. Marked coronary insufficiency was found in 0.4% in the 5th decade, 1.5% in the 6th decade, 2.2% in the 7th decade, 4.2% in the 8th decade and 10.3% in the 9th decade. 3) Diagnosis of left ventricular hypertrophy was made by Sokolow-Lyons' voltage criteria of SV1+RV5>35mm. Left ventricular hypertrophy was found in 7.6% in the 5th decade, 10.5% in the 6th decade, 15.1% in the 7th decade, 12.2% in the8th decade and16.6% in the9th decade. 4) Incomplete RBBB was found in 5.1% in the5th decade, 2.6% in the6th decade, 3.7% in the 7th decade, 4.2% in the 8th decade and 0% in the9th decade. This indicicates that incomplete RBBB in younger adults is due to functional rightventricular overload as in the athlete's heart and that in senile subjects due to organic arteriosclerotic changes of the conduction system. Percentage occurrence of atrial and ventricular premature beats increased with advance in age. 6) Serum total cholesterol was related neither to blood pressure nor to age. 7) Proteinuria was found in 5% of the subjects studied. Among them, hypercholesterolemia was found in 1 of 6 cases in the 5th decade, 2 of 7 cases in the6th decade, 11 of 20 cases in the 7th decade, 9 of 18 cases in the 8th decade and 3 of 4 cases in the 9th decade. 8) In subjects with proteinuria, moderate to marked coronary inssfficiency was found in 5 of 8 cases in 6th decade, 9 of 20 cases in the 7th decade, 11 of 21cases in the 8th decade and 3 of 4 cases in the 9th decade. Namely, abnormal electrocardiograms were observed in 47.1% of those with proteinuria. This indicates that myocardial ischemia occurs more frequently in those with renal. arteriosclerosis than. those without it. 9) Glucosuria was found in 106 of 935 subjects studied. Hypercholesterolemia higher than 200mg/dl was found in 72.7% of those with glucosuria. Abnormal electrocardiograme such as moderate to marked coronary insufficiency, left ventricular hypertrophy and myocardial infarction were found in 57.6% of those with glucosuria. This indicates that abnormalities in. carbohydrate metabolism accelerate aging process of the heart. 10) Abnormal electrocardiograms including mild coronary insufficiency of our criteria amounted to 49.0% in the5th decade, 69.6% in the 6th decade, 82.8% in the 7th decade, 89.2% in the 8th decade and 94.9% in the 9th decade. This indicates that electrocardiographic abnormalities increase with advance in age, and the occurrence of electrocardiographic abnormalities is much higher than previously reported when the changes of the U wave are taken into consideration.