The topology of the magnetic stray fields created by grain boundaries and its influence on magnetization processes of laminated grain-oriented silicon steel sheets were investigated. It was found that the variations in the magnetic flux density in laminated sheets, caused by the magnetic stray fields at the grain boundaries of adjacent layers, can be as large as 0.1–0.12 T at the average level of magnetic induction 1.75 T in the core. The induction distribution along the rolling direction in adjacent layers near the grain boundaries changed according to the spatial distribution of the longitudinal component of the stray field.