The ultrasonic diagnostic device of this invention repeatedly Drive the probe, the ultra wave which was transmitted by Drive the aforementioned probe the color flow mapping signal processing unit which the blood degree of velocity of flow data of the blood current parts in the aforementioned suffering inspection body which receives the reflective echo which is obtained by reflecting in the suffering inspection body with the aforementioned probe, in each frame on the basis of the sending and receiving section and the aforementioned multiple reception signals which the multiple reception signals the sequential are generated, the sequential is generated and the afterimage treatment section and the aforementioned reception signal which do afterimage treatment the blood degree of velocity of flow data in the aforementioned each frame vis-a-visOf on the basis, to have with the fault picture signal treatment section which generates the B mode fault image frame data and aforementioned afterimage the image synthetic section which synthesizes the blood degree of velocity of flow data and the aforementioned B mode fault image frame data which were treated, to loop the aforementioned afterimage treatment section, the blood degree of velocity of flow data of the up-to-date frame and afterimage of the frame of time before from the up-to-date on the basis of the blood degree of velocity of flow data which was treated and decide, alteration passee stance coefficient dynamically the result of aforementioned loop decision and on the basis of the blood degree of velocity of flow data of the frame of time before from the up-to-date and the up-to-date.本発明の超音波診断装置は、探触子を繰り返し駆動し、前記探触子を駆動することにより送信された超音波が被検体において反射することにより得られた反射エコーを前記探触子によって受信し、複数の受信信号を逐次生成する送受信部と、前記複数の受信信号に基づき、各フレームにおける前記被検体中の血流部分の血流速度データを逐次生成するカラーフローマッピング信号処理部と、前記各フレームにおける血流速度データに対して残像処理を行う残像処理部と、前記受信信号に基づき、Bモード断層画像フレームデータを生成する断層画像信号処理部と、前記残像処理された血流速度データおよび前記Bモード断層画像フレームデータを合成する画像合成部とを備え、前記残像処理部は、最新のフレームの血流速度データと最新より以前のフレームの
