Sacrificial specimen is a small sized fatigue specimen which is designed so that fatigue crack may be produced in the specimen sufficiently earlier than in the structural member when it is fixed to the structural member. The purpose is to predict a timing at which fatigue damage will actually appear in a structural member on the basis of information obtained by monitoring a fatigue damage condition of the sacrificial specimen. The main body of the sacrificial specimen developed in this study is a thin plate which has an artificial crack in the center of the specimen. The main body has a length of 60 mm, a width of 10 mm and a thickness of 0.25 mm and is made of the same material as the structural member. Very thin Teflon film is wound around the central portion of the main body including the artificial crack. After that, the main body is sandwiched between two thin epoxy resin plates and cemented together by means of adhesive agent. The total thickness of the completed sacrificial specimen is about 1 mm. The sacrificial specimen is cemented on the surface of smooth specimen and notched specimen using the same adhesive agent, and fully reversed fatigue tests are carried out under axial loading. It is found that the developed sacrificial specimen shows good performance in the fatigue test. Followings are made clear throughout the fatigue test. 1) Buckling and peeling do not take place during the fatigue test under the fully reversed stress amplitude. 2) Stress concentration factor of sacrificial specimen is about 5. 0 for crack initiation life. Fatigue life prediction is possible when it is applied to the location at which stress concentration is less than 5.0. 3) The sacrificial specimen has an enough monitoring period from crack initiation to failure.