Utrasonic burst phase thermography technology used the ultrasonic as heat source to heat the material , if there are some defects(crack or delaminition) in the sample, the ultrasonic energy will cause the fiction or thermal elastic effect of the place where the defects is. At the meantime, an infrared camera controlled by the computer are used to detect the thermal wave sequences and collect the information. Then processing the original thermal sequence by Fourier transforrmation, the amplitude and phase information of the defects in the material are obtained. In this paper, two laser welded seams which are welded by different laser powers and a wheel of an electronic motor saw were detected by this method, and the amplitude and phase information was shown as images.