  In this paper we study the symmetry protected Majorana edge states for the Z2
topological order of the Wen-plaquette model and the toric-code model and
calculate the dispersion of the Majorana edge states. For the system with
translational symmetry, the Majorana edge states are gapless and have the nodal
points at k=0 and k=pi. For the edge states of the toric-code model without
translational symmetry, the edge modes become gapped.
