Embodiments of adaptively performing clutter filtering are disclosed. In one embodiment, by way of non-limiting example, an ultrasound system comprises: an ultrasound data acquisition unit configured to transmit and receive ultrasound signals to and from a target object to output a plurality of ultrasound data corresponding to each pixel of a color Doppler mode image; and a processing unit in communication with the ultrasound data acquisition unit and being configured to calculate a power difference value corresponding to each of the pixels based on the plurality of ultrasound data, determine whether the power difference value is equal to or larger than a first threshold value, and if the power difference value is equal to or larger than the first threshold value, then perform first clutter filtering upon the plurality of ultrasound data, or if the power difference value is less than the first threshold value, then perform second clutter filtering upon the plurality of ultrasound data.