In recent years, mechanical structures such as railway wheels, rails, offshore structures, bridges, engine components, load bearing parts of automobiles, etc. have to endure for a long term up to 10 8-10 10 loading cycles in order to save resources and to reduce the cost together with the environmental load to the globe. Thus, the fatigue behavior of structural materials in the very high cycle regime of 10 8-10 10 cycles has become an important subject of the research. In this paper, a review of the current studies in this area performed by many researchers is described in order to provide a certain milestone in the history of the research on fatigue behavior of the metallic materials in the very high cycle regime.