  Based on the IR-improved bulk holographic AdS/QCD model which provides a
consistent prediction for the mass spectra of resonance scalar, pseudoscalar,
vector and axial vector mesons, we investigate its finite temperature behavior.
By analyzing the spectral function of mesons and fitting it with a Breit-Wigner
form, we perform an analysis for the critical temperature of mesons. The
back-reaction effects of bulk vacuum are considered, the thermal mass spectral
function of resonance mesons is calculated based on the back-reaction improved
action. A reasonable melting temperature is found to be $T_c \simeq 150 \pm 7$
MeV, which is consistent with the recent results from lattice QCD simulations.
