Abstract: The ultrasonic testing method, time, recordings and acceptance level of pressure vessel heavy low-alloy steel forgings in pressure water reactor (PWR) main loop are compared. Standards sameness and difference have been discussed with service performance, manufacture ability, engineering feedback, ultrasonic testing method and manufacture quality problems. It is helpful to draft ultrasonic testing specifications of pressure vessel heavy forgings in pressure water reactor main loop and improve ultrasonic testing operation in manufacture process.