Embodiments for arranging a 3D (three-dimensional) ultrasound image are disclosed. In one embodiment, by way of non-limiting example, an ultrasound system comprises: a storage unit for storing a plurality of reference position information each corresponding to a plurality of target objects a user input unit configured to receive input information for selecting a target object an ultrasound data acquisition unit configured to transmit and receive ultrasound signals to and from the target object to thereby output ultrasound data and a processing unit in communication with the storage unit, the user input unit and the ultrasound data acquisition unit, the processing unit being configured to form a 3D ultrasound image based on the ultrasound data and perform position arrangement of the 3D ultrasound image based on reference position information corresponding to the input information.
