Embodiments of performing beam forming processing based on sampling data in an ultrasound system are disclosed. The ultrasound system includes an ultrasound data acquisition unit configured to form a receive signal based on an ultrasound signal reflected from a target object, perform an analog-to-digital conversion on the receive signal to form sampling data, select pixels, which the respective sampling data are used as pixel values thereof among the plurality of pixels, cumulatively assign the corresponding sampling data to the selected pixels and perform beam forming upon the cumulatively assigned sampling data for the respective pixels to form receive-focused data.
