Provided is an ultrasound diagnosis apparatus including: an image processor configured to generate, as an amount of a contrast agent introduced into a target tissue of an object changes, a plurality of ultrasound images showing different sizes of regions in a target tissue region representing a tissue into which the contrast agent has been introduced； a display configured to display a first ultrasound image from among the plurality of ultrasound images； a user input unit configured to receive a user input for setting a region of interest (ROI) in the displayed first ultrasound image； and a controller configured to determine, based on the set ROI, the regions in the plurality of ultrasound images representing the tissue into which the contrast agent has been introduced and determine the region of the target tissue based on the determined regions.
