The behaviors of magnetoacoustic emission (MAE) on cold-rolled and thermally aged Fe-Cu model alloy were investigated. The rms voltage of MAE increases with increasing reduction ratio before thermal aging due to the increase in dislocation density. As to thermal aging, the significant changes were not found on the behaviors for the undeformed specimen. This indicates the morphological change of copper precipitation has no strong effect to the interaction between domain walls and their pinning sites. On the other hand, the rms decreases when aging time elapses for the cold-rolled specimen at first, and then increases in aging over 10³ minutes. These behaviors can be explained on the basis of the microstructure changes including dislocations and copper precipitation.