Quantum teleportation is a transfer protocol of quantum states, which cannot be realized only with classical physics. The essence of this protocol is quantum entanglement, which was proposed by Einstein as a counter example for quantum mechanics. In terms of quantum information processing, quantum teleportation can be regarded as an “Identity” operation. So one can modify the quantum circuit to make an arbitrary operation and universal quantum computing. One of the application of the quantum computing is “quantum version of coherent communication”, which enables us to get the channel capacity beyond the classical limit (Shannon limit).