  We reexamine the electronic structure of graphene on SiC substrate by
angle-resolved photoemission spectroscopy. We directly observed multiply
cloning of Dirac cone, in addition to ones previously attributed to
reconstruction. The locations, relative distances and anisotropy of Dirac cone
replicas fully agree with the moir\'e pattern of graphene-SiC heterostructure.
Our results provide a straightforward example of moir\'e potential modulation
in engineering electronic structure with Dirac fermions.
