Abnormal Goss grain growth in a conventional grain oriented (CGO) Fe-3%Si electrical steel is analysed using OIM(TM) (Orientation Imaging Microscopy) after several annealing times. Misorientation of boundaries surrounding the growing Goss grains are characterized. In these conditions, it appears that the two main theories, based on Coincident Site Lattice (CSL) boundaries or on high energy (HE) boundaries misoriented by 20-45degrees, cannot be applied to explain the difference of boundary migration rate during the secondary recrystallisation.