Abstract: Phased array (PA) ultrasonic technology has the advantages that the elements of search units can be excited in amplitude and delay by computer, and the beam parameters such as angle, focal distance and focal spot size can be adjusted by software. This paper outlines the application classification and practical examples, including manufacturing and service inspections used in the aerospace industry, nuclear power equipment and pressure equipment etc. Main on its emphasizes are put on its suitability to the objects with complicated shape, or with limited approach areas, and superiority over defect sizing and characterization. Also, the relevant standardization of PA as a basis of application, and the performance demonstration as the necessary procedure specified by the code are introduced. The intention is to provide a reference for spreading the new technology in our country.