Abstract: Artificial defects play important role in nondestructive method qualification. The reliability and accuracy of NDT qualification result is determined by quality of artificial defect. In this article, fabrication methods of artificial defects is recommended in NDT qualification of subsea pipeline. The defects are made by buried obstacle, variation of welding parameter and machining to simulate natural defect and control size, position, orientation to improve success rate. Time of flight diffraction, radiographic testing and destructive test are recommended to evaluate artificial defect. The artificial defects of high quality are made for NDT method qualification eventually.