An ultrasonic diagnosis apparatus comprising: an image data acquisition unit (15, 17) adapted to acquire ultrasonic image data corresponding to each time phase in a first period including at least one contraction and one expansion by ultrasonic scanning throughout the first period for an observation region of a soft tissue not having active dynamics as an object to be examined, the observation region repeating contracting motion and expanding motion due to an external dynamic load toward the observation region including repetition of compression and release; a velocity information generating unit adapted to generate, from the ultrasonic image data, velocity information concerning a tissue in the observation region in each time phase in the first period; a reference information generating unit adapted to generate, from the velocity information, reference information that is represented by a graph on velocities of the observation region with time, over the first period; a strain information generating unit adapted to determine, from the reference information, a reference time phase, and to generate strain information concerning the tissue in the observation region by executing time integration with respect to the velocity information based on the reference time phase, the reference information and the velocity information, the reference time phase being a time phase corresponding to one of the contracting motion and the expanding motion, wherein the time integration is executed over a second period including at least part of the compression or the release, respectively; an image generating unit adapted to generate, based on strain information, a strain image indicating elasticity of the soft tissue; and a display unit adapted to display the strain image in a predetermined form. an image data acquisition unit (15, 17) adapted to acquire ultrasonic image data corresponding to each time phase in a first period including at least one contraction and one expansion by ultrasonic scanning throughout the first period for an observation region of a soft tissue not having active dynamics as an object to be examined, the observation region repeating contracting motion and expanding motion due to an external dynamic load toward the observation region including repetition of compression and release; a velocity information generating unit adapted to generate, from the ultrasonic image data, velocity information concerning a tissue in the observation region in each time phase in the first period; a reference information generating unit adapted to generate, from the velocity information, reference information that is represented by a graph on velocities of the observation region with time, over the first period; a strain information generating unit adapted to determine, from the reference information, a reference time phase, and to generate strain information concerning the tissue in the observation region by executing time integration with respect to the velocity information based on the reference time phase, the reference information and the velocity information, the reference time phase being a time phase corresponding to one of the contracting motion and the expanding motion, wherein the time integration is executed over a second period including at least part of the compression or the release, respectively; an image generating unit adapted to generate, based on strain information, a strain image indicating elasticity of the soft tissue; and a display unit adapted to display the strain image in a predetermined form.