Provided is a three-dimensional (3D) ultrasound system for intuitively displaying a change in motion and a method of operating the 3D ultrasound system. The 3D ultrasound system may include a scan unit to generate ultrasonic data of an object through scanning, a coordinate determination unit to determine first coordinates corresponding to a top end of the object, and second coordinates corresponding to a bottom end of the object, from the ultrasonic data, and a display control unit to measure a vector length from the first coordinates to the second coordinates, and to display a color corresponding to the measured vector length by mapping the color to the ultrasonic data.
