Abstract: In this thesis，following ASTM E2491—2008, by experiments，we studied beam focusing behavior and beam steering behavior of ultrasonic phased array system in the case of being with and without a shear wave wedge fixed to the probe. Influence of aperture setting，focusing depth setting and steering angle setting to beam focusing behavior and beam steering behavior are studied by changing different values of these parameters. Then we summarize that，the acoustic beam can only be focused in its near field，the method of determination of phased array beam steering limits offered in ASTM E2491 actually attribute to measure the angle resolution.