Provided is an ultrasound imaging apparatus an image processor configured to acquire, based on three-dimensional (3D) ultrasound data for generating a 3D ultrasound image of an object, at least one two-dimensional (2D) ultrasound image comprising at least one reference ultrasound image corresponding to at least one reference cross-section a controller configured to set a user-designated reference cross-section obtained by moving a first reference cross-section included in the at least one reference cross-section and control generation of at least one first ultrasound image corresponding to the set user-designated reference cross-section and a display configured to display the generated at least one first ultrasound image.
