A sign of palpitation above the umbilicus is an important piece of information which means a disorder of Ki circulation in the Kampo medicine. This study revealed that the amplitude of this palpitation observed in the abdominal wall was about 4 mm. The author has been speculated for a long time that this sign should accompany significant change of the diameter of abdominal aorta. But this speculation was denied by MRA study, which showed at most 1.5 mm change of the diameter of abdominal aorta. The ultrasonic studies of abdominal aorta showed that the amplitude of diameter of the aorta changed about 1.5 mm. The discrepancy between the amplitude of abdominal wall (4 mm) and that of ultrasonic image (1.5 mm) could be explained by assuming the impulse force toward the abdominal aorta wall. Concerning the generated powerful impulse, the author considered three factors including increased pulse velocity, reaction force by the spine and the sound pressure generated in the heart.