Asymmetric rolling has been considered as a possible way to obtain severe plastic deformation (SPD) since it will give an extra shear deformation to the processed materials during rolling. Previous researches have confirmed such a shear deformation. Very recently, the method of inserting-block is used to characterize the shear deformation through direct observation, but when the reduction is more than 70%, the lineation scratched on the side face of internal mark becomes vague and illegible. In order to directly observe the shear deformation of metallic material with large reduction, the internal mark method is employed in this research and asymmetric rolling was performed with pure aluminum and iron at room temperature. In severe plastic deformation, the shear deformation caused by asymmetric rolling was clearly observed and measured through employing internal mark method. Remarkable extra shear deformation during asymmetric rolling was confirmed. Very high equivalent strains were achieved when sheet samples were asymmetrically rolled to high reduction ratio. These strain values fall into the range of SPD.