Abstract: In order to investigate the effects of notch geometry and loading conditions on the fatigue initiation life and fatigue fracture life of 16MnR material,fatigue experiments were conducted for both smooth rod specimens and notched rod specimens.The detailed elastic-plastic stress and strain responses were computed by the finite element software（ABAQUS） incorporating a robust cyclic plasticity model via a user subroutine UMAT.The obtained stresses and strains were applied to the multiaxial fatigue damage criterion to compute the fatigue damage induced by a loading cycle on the critical material plane.The fatigue initiation life was then obtained by the proposed theoretical model.The well agreement between the predicted results and the experiment data indicated that the fatigue initiation of notched components in the multiaxial stress state related to all the nonzero stress and strain quantities.