  We propose a method to calculate the QCD level density directly from the
thermodynamic quantities obtained by lattice QCD simulations with the use of
the maximum entropy method (MEM). Understanding QCD thermodynamics from QCD
spectral properties has its own importance. Also it has a close connection to
phenomenological analyses of the lattice data as well as experimental data on
the basis of hadronic resonances. Our feasibility study shows that the MEM can
provide a useful tool to study QCD level density.
