An ultrasonic diagnostic apparatus capable of measuring a three-dimensional motion of a biological tissue in a short time. An image processor creates volume data based on image data of a B-mode image of a biological tissue and creates image data of a series of tomographic images in time series for the respective two or more sectional positions based on the volume data. A controller displays one tomographic image for each sectional position on a display part. A user operates an operation part to designate a measurement image region on the displayed tomographic image. A displacement calculating part calculates a displacement in time series of the designated measurement image region for each sectional position. A motion information calculating part calculates motion information of the biological tissue based on the displacement of the measurement image region calculated for each sectional position.
