Abstract: The influence of stainless steel cladding on ultrasonic examination was evaluated particularly in this article. It mostly includes following three aspects: Coarse grain of stainless steel cladding brings larger acoustic attenuation and decreases ultrasonic examination sensitivity; Beam distortion leads to big defect position error; And it is easy to form false defect due to cladding. Therefore, many methodologies were put forward to overcome the influence of cladding on ultrasonic examination, including for instance, making reference block, correcting defect position, and distinguishing and analyzing false defect.