  In this work, we investigate quantum Fisher information(QFI) and quantum
coherence(QC) of an atom in dissipative cavity. In zero temperature reservior
and with one excitation number, we obtain the analytical solutions of QFI and
QC as well as their relationship for Ohmic and Lorentzian reservoir,
respectively. The results show that both of the atom-cavity coupling and the
cavity-reservoir coupling can effectively protect QFI and QC. Especially, QFI
and QC will tend to their stable values when the atom-cavity coupling or the
cavity-reservoir coupling is larger than a certain value. QC can augment QFI
and can effectively improve the quantum metrology. In addition, we give a
physical explanation of the dynamic behavior of QFI and QC by using the
decoherence rate.
