▎ 摘　　要

This contribution reports on comparative studies on giant magnetoresistance in carbon nanotubes and graphene nanoribbons of similar aspect ratios (i.e. perimeter/length and width/length ratios, for the former and the latter, respectively). The problem is solved at zero temperature in the ballistic transport regime, by means of the Green functions technique within the tight-binding model mid with the so-called wide band approximation for electrodes. The giant magnetoresistance effect in graphene is comparable to that of carbon nanotubes, it depends strongly on the chirality and only slightly on the aspect ratio. It turns out that; graphene, analogously to carbon nanotubes may be quite an interesting material for spintronic applications.