An ultrasonic diagnostic apparatus for collecting correct strain information irrespective of the depth of an object. The ultrasonic diagnostic apparatus comprises an ultrasonic probe for transmitting/receiving ultrasonic waves to/from an object, pressing means for pressing biological tissues of the object, transmission means for transmitting ultrasonic waves to the biological tissues via the ultrasonic probe, reception means for receiving the reflected echo signals generated from the object via the ultrasonic probe, strain information calculating means for calculating the strain distribution of the biological tissues on the basis of the data on a pair of frames at different acquisition times received by the reception means, strain image construction means for constructing the strain image according to the strain distribution determined by the strain information calculating means, and display means for displaying the strain image. The ultrasonic diagnostic apparatus further comprises strain distribution correcting means for correcting strain distribution by using a strain distribution correcting function defined under the press condition of the press by the pressing means. Therefore, corrected strain information can be collected irrespective of the depth of the object.
