Abstract: The new requirements for TOFD technique specified in the latest edition (2006 addenda) of the ASME Code were presented. The second part is the requirements for interpretation of images as TOFD results. First of all，it gives an outline of the principle of reading a grayscale image and the rules of locating and measuring flaw indications. Then it analyzes the typical images with 22 examples of flaws in welds. Learning by analogy, we can get guidelines for performing TOFD and evaluating results of inspection on pressure vessels.