The present invention relates to an ultrasonic echographic diagnostic apparatus which is capable of displaying the characteristics and properties of tissue, such as the maximum displacement of tissue, the hardness of tissue, the velocity of propagation of vibrations through tissue, and the magnitude and direction of movement of tissue, in various display modes. The apparatus is capable of detecting and displaying the displacement of tissue caused by heartbeat or external pressure in a real-time mode by calculating the minute displacement of tissue or the differential of the same, calculating a temporal local maximum of the minute displacement varying with time, time corresponding to the temporal local maximum, the gradient of the time and the absolute magnitude of the gradient, and displaying the results of the calculations. In another aspect of the invention, the apparatus specifies a desired point or points and a desired direction or directions in a tomogram, determines calculating data passing a desired point and extending along a desired direction, for a plurality of tomograms obtained at different times, respectively, by interpolating the data signals, determines the displacement of the desired point in the desired direction or the rate of change of the displacement on the basis of the calculating data, and displays the information calculated on the basis of the displacement or the rate of change of the displacement.