Disclosed herein are a method for estimating acoustic velocity of an ultrasonic image and an ultrasonic diagnosis apparatus using the same. The method for estimating acoustic velocity of an ultrasonic image includes: (A) dividing each of the ultrasonic images into a plurality of blocks (B) extracting contours of ultrasonic images for each block of one frame among the ultrasonic images (C) calculating and analyzing average luminance values of each block (D) determining the optimal block number using the average luminance values and selecting the optimal blocks and (E) estimating and applying the real acoustic velocity, whereby the acoustic velocity is estimated in real time and is applied to the ultrasonic diagnosis apparatus.
