An ultrasound diagnostic apparatus which can show dynamic blood flow more accurately than ever without reducing the frame rate of the blood flow image is provided. The ultrasound diagnostic apparatus of the present invention includes: an ultrasound transmitting/receiving unit for receiving an echo signal dynamic blood flow detection unit for calculating a predetermined detection value based on dynamic blood flow in a test subject based on the echo signal a luminance value conversion unit for converting the predetermined detection value into a luminance value a luminance value replacement unit retaining luminance value conversion information for converting one luminance value to another luminance value and a comparison unit for comparing a first luminance value in one frame with a second luminance value in the frame immediately preceding the one frame, out of the luminance values outputted from the luminance value conversion unit, wherein the comparison unit is adapted to output either the first luminance value or a third luminance value which is not larger than the absolute value of the second luminance value, based on the comparison result and the luminance value replacement information.
