The disclosure provides an ultrasound image registration apparatus and a method thereof suitable for registering two ultrasound images partially overlapped with each other. The apparatus comprises: a first-stage image-developing processing module, a second-stage image-developing processing module and a registration module. The first-stage image-developing processing module performs beam-forming processing on two ultrasound images so as to generate two raw images. The second-stage image-developing processing module connects the first-stage module for performing envelope detection processing and compression processing on the raw images so as to generate two developed ultrasound images. The registration module connects the two image-developing processing modules for respectively obtaining coordinate information of at least one feature point of the raw images as the initial values of an image registration procedure, and for performing speckles-reducing processing on the developed ultrasound images and using the speckles-reduced ultrasound images to perform the image registration procedure.
