An ultrasound imaging apparatus and a controlling method thereof are provided. The ultrasound imaging apparatus acquires a plurality of ultrasound contrast agent images of a region of interest of the object after an ultrasound signal for destroying a contrast agent is transmitted to the region of interest of the object, into which the contrast agent is injected, at time intervals of tk (k 1, 2, ..., n, and n is an integer of 2 or more), generates a kth cumulative ultrasound contrast agent image by accumulating the acquired ultrasound contrast agent images at every time intervals of tk to generate n cumulative ultrasound contrast agent images, and displays the generated n cumulative ultrasound contrast agent images, wherein tk satisfies tk >； tk-1.
