1. On measuring the values in various parts of the heart in fluorograms, it was examined how they change in ten years. The result of the examination showed that the aortic arch diameters right and left, the transverse diameters on the left increased in proportion to the increase of man's age. The rate of increase, however, was not the same in age; generally, the older a man is, the greater the percentage of increase will be; the left transverse diameters showed the greatest rate of swell in the age from twenties to thirties. 2. About the relation between age and cardiac measurements, every measured value, except the right transvers diameters, was proved to be greater in the older age. The right transverse diameters registered its highest value in the age from thirties to forties without reference to blood pressnre. 3. In regard to the transition of blood pressure and cardiac measurements over ten years; the notable increase in the aortic arch diameters and the left transverse diameters of high blood pressure group was perceived, as compared with the normel blood pressure group. In the left aortic arch diameters and the left transverse diameters, the high blood pressure group showed twice as much rate of increase as the normal blood pressure group. 4. About the relation between blood pressure and cardiac measurements, the high blood pressure group showed greater value than the normal blood pressure group in the left transverse diameters and the aortic arch diameters right and left.