  I review recent progress in relating meson spectral function to imaginary
time correlation function at finite temperature calculated on isotropic as well
as on anisotropic lattices. Special attention is payed for the lattice
artifacts present in calculation of meson spectral functions. Results in the
case of light quarks as well as heavy quarks are reviewed which indicate in
particular that even in the chiral limit meson spectral functions have
non-trivial structure and the ground state quarkonia survive up to temperature
1.5T_c
