Disclosed are an ultrasound diagnostic apparatus and an operating method thereof. The operating method includes displaying an ultrasound image of a target object, receiving an ultrasound signal obtained from a moving object of interest (OOI) included in the target object, setting a first reference region in the ultrasound image, acquiring first moving path information of the OOI passing through the first reference region, based on the received ultrasound signal, and displaying the first moving path in the ultrasound image, based on the first moving path information.