  The concatenated Greenberger-Horne-Zeilinger (C-GHZ) state is a new type of
multipartite entangled state, which has potential application in future quantum
information. In this paper, we propose a protocol of constructing arbitrary
C-GHZ entangled state approximatively. Different from the previous protocols,
each logic is encoded in the coherent state. This protocol is based on the
linear optics, which is feasible in experimental technology. This protocol may
be useful in quantum information based on the C-GHZ state.
