Fracture behavior and pipe strength are very important to the integrity of energy plants. The pipes of energy plants are subject to local wallthinning, resulting from. severe erosion-corrosion damage. Therefore, evaluation of failure pressure and fracture behavior of pipes in energy plants must be needed for getting integrity of them. In this study, the pipe failure tests were performed on carbon steel pipe with various local wall thinning shapes, wall thinning length, wall thinning depth. The tests were conducted under internal pressure. The results of tests showed that failure mode of wall thinned pipe depended on magnitude of internal pressure and wall th inning length as well as wall thinning depth .In this study, we investigated Acoustic emission signal by burst test and the results of the frequency range would be expected to be basic data that inspect energy plant in real-time