To provide an ultrasonic diagnostic apparatus capable of correctly measuring the diameter of a blood vessel or a vascular wall from positional variation of a predetermined region including blood vessels of a subject by tracing the movement of the predetermined region.

The ultrasonic diagnostic apparatus includes: a region of interest setting unit (125) for setting a first region of interest (ROI) and a second region of interest (ROI) on a vertical straight line at a right angle to the long axis direction of a blood vessel on a wall of the blood vessel in an ultrasonic image at a predetermined time which is generated based on the ultrasonic data stored in a first memory unit and displayed on a display unit; a tracing unit (122) for tracing movement of tissue in the subject corresponding respectively to the first and second ROIs in each of the ultrasonic images from the designated time to sequentially following thereafter by a gradient method using a spatial brightness gradient; and a memory unit (115) for storing information of the movement of the tissue for a predetermined duration on the basis of the movement of the tissue traced by the tracing unit.