Recently, many kinds of the pipelines are used due to expansion of residential area. These pipes are manufactured with various diameters depending on the purpose and environment. Generally, the decrease in fatigue life as the size of the structure increases is well known, but there is not much information on the effect of the curvature of the pipe on the fatigue life. In this study, standard specimens and curved plate specimens including the curvature were collected from the API 5L X42 pipe. For the curved plate specimens, the widths of parallel parts were made to be 20 mm, 40 mm, and 60 mm in order to evaluate the effect of curvature inclusion degree. Also, the jigs were designed by paying attention to the alignment of the test equipment during the fatigue test, because the curved plate specimens are including the curvature of pipe. As a result of the fatigue test, the fatigue life reduction due to the curvature of the pipe was very slight. Therefore, if the bending moment does not act on the specimen, it can be seen that the curvature does not affect the fatigue life.