  We propose a quantum communication protocol that can be used to transmit any
quantum state, one party to another via several intermediate nodes, securely on
quantum communication network. The scheme makes use of the sequentially chained
and approximate version of private quantum channels satisfying certain
commutation relation of $n$-qubit Pauli operations. In this paper, we study the
sequential structure, security analysis, and efficiency of the quantum
sequential transmission (QST) protocol in depth.
