An investigation of the elastic and plastic anisotropy of polycrystal in the vicinity of the fatigue-crack tip is of both scientific and practical significance to promote a fundamental understanding of the fatigue-crack-deformation behavior. Recently, we simulated the hkl strain evolution during the uniaxial tensile test using a microstructure-base plasticity finite-element model. It is in good agreement between micromechanical models and neutron-strain measurements. Therefore, we are going to extend this micromechanical model on a compact-tension specimen with a fatigue crack by combining a previously-developed irreversible and hysteretic cohesive-interface model to simulate the hkl strain evolution near the fatigue-crack tip.