The present invention proposes an ultrasound system and method of identifying a vessel of a subject. The ultrasound system comprises: an ultrasound probe configured to simultaneously acquire a sequence of ultrasound blood flow data frames (such as a sequence of ultrasound Doppler data frames) and a sequence of ultrasound B-mode data frames of a region of interest including the vessel over a predetermined time period； a blood flow region selecting unit configured to select a blood flow region in the sequence of blood flow data frames； and a vessel segmenting unit configured to segment the vessel in at least one frame of the sequence of ultrasound B-mode data frames based on the selected blood flow region. Since there is no need to manually place any seed point for vessel segmentation any more, the user dependency is reduced and a fast measurement is made possible. Furthermore, since the segmentation of the vessel in a B-mode data frame makes use of information from multiple blood flow data frames, more robust, reliable segmentation can be achieved.
