Ultrasound diagnosis apparatus comprises an image generator, a first structural information acquirer, a second structural information acquirer, and a synthesizer. The image generator generates, based on ultrasound waves transmitted and received in accordance with a plurality of transmission and reception conditions, sets of image data whose images represent at least partially a common area for each of the transmission and reception conditions. The first structural information acquirer acquires tissue-structure information indicative of tissue structures depicted, respectively, in the sets of image data. The second structural information acquirer acquires common structural information indicative of a tissue structure common in the sets of image data, based on the tissue-structure information. The synthesizer changes the method of image-synthesis applied on the sets of image data, a different method for each of the image areas distinguished based on the common structural information, and generates composition image data based on the sets of image data.
