To provide an ultrasonic system and method which never cause a drop-out phenomenon in an elastic image.

The system includes: an ultrasonic data acquisition unit 110 which acquires first ultrasonic data corresponding to a first frame in a state without compression to an object, and acquires second ultrasonic data corresponding to a second frame in a state after compression to the object; and a processor 120 which performs correlation operation between a plurality of windows of the first frame and a plurality of windows of the second frame to calculate displacement in each of a plurality of windows of a third frame corresponding to the elastic image, and forms the elastic image. The processor 120 sets, based on a current position of the window in the N-th line in the axial direction of the third frame, a window on the (N-i)-th line, sets an initial displacement based on the displacement corresponding to the window, sets an axial moving range of the window to the second frame based on the initial displacement, and moves the window of the second frame in the axial direction.