Abstract: Some important specifications of ultrasonic testing(UT) for welded joints of pressure equipment offered by ASME BPVC Code were outlined, including the quantifying requirements of UT procedures, the type and characteristics of the calibration blocks, the plotting and form of the DAC curves, and the demands on indication characterization and measurement and classification in the acceptance criteria and so on. A comparison was made between the ASME Code and the chinese standard JB 4730, aiming at providing a reference for the UT standard of pressure vessels linking or harmonizing with international standard.