Abstract: The application of automatic ultrasonic testing for the inspection of butt girth welds of pipeline was introduced. Automatic ultrasonic testing, manual ultrasonic testing and radiographic testing techniques were used on the inspection of embedded defects. Comparisons between existing testing results showed that automatic ultrasonic testing had great advantages and bright application future. Final conclusion was drawn that the combination of both time of flight diffraction technique and pulse echo technique was effective for the butt girth welds testing of pipeline.