For spheroidal graphite iron, FCD 80, and the same material with plasmasprayed Alumina coating, the axial-load fatigue tests were carried out at elevated temperature of 350-550°C. The fatigue limit of FCD 80 at elevated temperatures was improved by the plasma-sprayed Alumina coating. Through fractography using SEM, it was found that the crack initiated at an inner porosity of micro casting defect in Alumina-coated FCD 80 and that the fish eye was formed on the fracture surface. On the other side, the fatigue crack originated from the surface porosity in FCD 80. Thus, it could be concluded that the improvement in the fatigue limit of FCD 80 at elevated temperatures would be caused by the prevention of propagation of "metallurgical crack" due to which had been formed from a surface porosity.