The chemically induced interface migration (CIIM) has been observed in $Al_2O_3-Cr_2O_3$ system. When Lucalux (highly dense $Al_2O_3$ containing small amount of MgO in ppm level) is heat-treated at 1500℃ with $Al_2O_3-Cr_2O_3$ powder of various composition, the grain boundaries migrate away from their centers of curvature, producing corrugated or faceted grain boundaries. Considerable amount of $Cr_2O_3$ is detected in the migrated regions. The boundary migration in this oxide appears to be similar to those observed in metal systems and the migration behavior is consistent with the driving force arising from the coherency strain in the diffusion zone ahead of the migrating grain boundaries.