Ni-based speralloys have been widely used to make the blade parts of the advanced aeroengines for their high temperature tolerance and good mechanical property. During high temperature service, the materials endure the effects of temperature and alternating load, causing high-cycle fatigue deformation on the hot-end components. Meanwhile, the fatigue behaviors of the alloy are closely related to the deformation mechanisms and its microstructure characteristics, such as the size, distribution and morphology of γ' phase and carbides, and the fatigue fracture of the using materials possesses unpredictability. Therefore, investigating fatigue behaviors of the material is of significance in alloy design and life prediction. But the high-cycle fatigue behavior of K416B superalloy with high W content is still unclear up to now. For this reason, by means of high-cycle fatigue property measurement and microstructure observation, the high-cycle fatigue behavior of K416B Ni-based superalloy at 700 ℃ has been investigated. The results show that at 700 ℃ and stress ratio R=-1, the high-cycle fatigue life of K416B superalloy decreases with the stress increasing, and high-cycle fatigue strength of the alloy is 175 MPa. At the condition of low stress amplitude, the deformed dislocations may slip along different orientations in the matrix. With the stress amplitude increasing, the dislocations may shear into γ' phase and form the stacking fault. During tension and compression high-cycle fatigue, multiple slip systems are activated in the alloy, and the distortion occurs along various directions, resulting in stress concentration on the regions of γ +γ' eutectic and carbides. The crack sources may be initiated at the eutectic and blocky carbide near the surface of the alloy. As high-cycle fatigue goes on, the cracks propagate along the inter-dendrite in expansion region, and the typical cleavage fracture occurs in the final rupture region.