The unique texture evolution and secondary recrystallization behavior of medium temperature reheated grain oriented silicon steel containing copper were analyzed by comparison with those of conventional grain oriented silicon steel and high permeability silicon steel. The results show that to obtain a strongerγ-fiber primary recrystallization texture, which can be easily consumed by Goss grains, recovery annealing and slow heating rate of high temperature annealing are necessary. During the high temperature annealing stage, the strongγ-fiber primary recrystallization texture shows the effects of decreasing the stored energy caused by recovery annealing and increasing the nucleation rate of γ-fiber grains with slow heating rate. The onset temperature of secondary recrystallization excee-ding 1000℃ and the strong γ-fiber primary recrystallization texture with less non-γ-fiber oriented grains indicate that the secondary recrystallization behavior is dominated by preferred grain growth. As a result, very huge secondary recrystallization grains with smooth boundaries are obtained. The iron loss is increased due to huge secondary grain size characterized in medium temperature reheated grain oriented silicon steel final products, but can be reduced significantly by magnetic domain refinement using laser scribing, compared with that of high permeability grain oriented silicon steel with small secondary grain size.