Ultrasonic imaging apparatus for color display of flow velocity

An ultrasonic imaging apparatus comprises an ultrasonic transducer for emitting an ultrasonic beam onto an interest region of a living body containing a blood flow and outputting an echo signal, a correlation circuit for determining a correlation of the signals obtained from the ultrasonic transducer and a velocity calculation circuit for calculating the velocity of the blood flow from the correlation data obtained by the correlation circuit. A zero shift process circuit zero-shifts the velocity data obtained from the velocity calculation circuit and compresses the zero-shifted velocity data in correspondance with an amount of zero shift. The zero-shifted flow velocity data is displayed within a possible display range.