Abstract: The paper analyzed the difficulties that JB/T 4730.2 beginner would meet during the learning of welding joint ray-inspection quality classification chart. The paper presented chart form classification, which subdivided the JB/T 4730.2 welding joint quality classification. And the single strip defect quality classification result chart was drawn to make welding quality classification easier understood by ray-inspector and also to simplify the photographic plate evaluation procedure.