Using three-dimensional mapping images at different time phases obtained by mapping motion information, a peak value of motion information in a local region is retrieved in each of the time phases. On the basis of the result, a locus line or the like indicative of fluctuations with time in the local peak region is generated and displayed so as to be, for example, superimposed on a mapping image. By observing the locus line on the mapping image displayed, the observer can directly grasp the state of the space-time propagation of mechanical excitement of the heart.
