There are disclosed embodiments for an ultrasound system (100) for providing a color M mode image and a brightness M mode image. The ultrasound system comprises: an ultrasound data acquisition unit (140) configured to perform a first operation for providing a first piece of ultrasound data for a color M mode image and a second operation for providing a second piece of ultrasound data for a brightness M mode image a control unit (130) configured to control the ultrasound data acquisition unit (140) to perform the first operation by an average number of times and the second operation one or more times in a selective pattern within a predetermined sweep period to respectively accumulate the first pieces of ultrasound data and the second pieces of ultrasound data provided from the ultrasound data acquisition unit (140) and an image processor (160) configured to form the color M mode image based on the accumulated first pieces of ultrasound data and to form the brightness M mode image based on the accumulated second pieces of ultrasound data.
