  The long-time maintenance of quantum coherence is crucial for its practical
applications. We explore decoherence process of a multiqubit system passing
through a correlated channel (phase flip, bit flip, bit-phase flip, and
depolarizing). The results show that the decay of coherence was evidently
delayed when the consecutive actions of the channel on the sequence of qubits
has some classical correlations. In particular, the relative entropy of
coherence for a system with large number of qubits is more robust than that
with small number of qubits. We also provide an explanation for the delayed
decoherence by exploring the interplay between the change of the unlocalized
quantum coherence and the total correlation gain of the multiqubit system.
