The experiments were carried out by using pure iron at very high rolling speed. The results showed that the grain size of the rolled products in some area is big or small corresponded by the grain size of the base. The deformation of the rolled metal was not only formed on the surface, but also infiltrated to the centre when the rolling speed is set to 100 m/s with the corresponded strain rate is 2 880 s -1 . The grain size of the rolled products fits well when the grain size of the base distributed well. In vertical section of the specimen, the grains were extended in longitudinal direction near the centre, but compressed in longitudinal direction near the surface. It is determined by the unique character of groove rolling.