The experimental and the analysis for effects of circumferentially local wall thinning on the fracture behavior of pipes were carried out. Local wall thinning for experimental was machined on the outside of pipes in order to simulate the metal loss due to erosion/corrosion. In addition, the pipes with local wall thinning on the inside were carried out FE analysis, and it made a comparative study with that of outside. Failure mode could be classified into ovalization, local buckling and crack initiation depending on the thinned length and thinned ratio. Three-dimensional elasto-plastic analyses were able to accurately simulate fracture behaviors of inner/outer local wall thinning. Therefore the fracture behavior of the inner local wall thinning can be estimated with the outer local wall thinning.