Abstract: Comparison and analysis of ferritic steel welds ultrasonic testing between JB/T 4730.3—2005 and RCCM-MC2600—2007 with addendum were made and the main content consisted of scope, the methods of checking, calibration or reference block, examination condition, power and gain setting, the defect assess, measure and grade. The object of the article is to help operators of company and let them master key points of steel welds ultrasonic testing, to ensure that products meet the technical and quality requirements.