Abstract: It was summarized in this paper the factors which influence the magnetostriction of grain oriented silicon steel. The AcDc magnetic properties measurement device, magnetostriction measurement device and magnetic domain viewer were used to investigate the influence of permeability and domain structure on the magnetostriction of grain oriented silicon steel. It was found that the domain deviation angle has direct influence to the maximum negative magnetostriction; the wedgelike domain has great influence on the saturated magnetostriction；the wedgelike domain can be reduced by laser scribing and thus magnetostriction can be decreased.

Key words: magnetostriction, magnetic domain, grain oriented silicon steel, permeability, laser scribing