▎ 摘　　要

We apply the topological classification theory using chiral symmetry to graphene nanoribbons (GNRs). This approach eliminates the requirement of time-reversal and spatial symmetry in previous Z(2) topology theory, resulting in a Z classification with the conventional Z index in a new vector-formed expression called "chiral phase index" (CPI). Our approach is applicable to GNRs of arbitrary terminations and any quasi one-dimensional chiral structures, including magnetism. It naturally solves a recent experimental puzzle of junction states at a class of asymmetric GNR junctions. We moreover derive a simple analytic formula for the CPI of armchair GNRs. Since this approach enables access to electron spin behavior, based on the CPI, we design a novel GNR with periodic localized moments and strong spin-spin exchange coupling.