There are disclosed embodiments for an ultrasound system for providing a color M mode image and a brightness M mode image. A control unit calculates a time period expected to perform a first operation for the color M mode image and a second operation for the brightness M mode image once respectively, and determines an acquisition pattern defining an order of performing the first and second operations based on the calculated time period, a sweep period, and an ensemble number. The control unit controls the acquisition unit to perform, within the sweep period, the first operation a number of times equal to the ensemble number and the second operation one or more times according to the acquisition pattern. An image processor forms the color M mode image based on the first ultrasound data and forms the brightness M mode image based on the second ultrasound data.
