Residual stress generated in an aluminum-alloy shrink fitted specimen was measured by neutron diffraction method and compared with calculated values by FEM analysis. The measured values agree with calculated ones when the diffraction has high intensity and sharp profile. However, the diffraction intensities were dependent on the measurement directions since the specimen possessed texture. Diffraction profiles in directions having a weak diffraction intensity caused an inaccurate evaluation of the residual stress. The measured strain can be modified with the ratio of elastic constant when the Poisson's ratio independ on diffraction plane like as Al alloy. The accuracy of residual stress measurement by the proposal method has better result than conventional method, if measured sample has strong texture.