  The thermal glueball is studied at finite temperature by using SU(3)
anisotropic lattice QCD with beta_{lat}=6.25, the renormalized anisotropy xi =
a_s/a_t = 4 over the lattice of the size 20^3xN_t with various N_t at the
quenched level. While the narrow peak ansatz leads to the significant polemass
reduction of about 300 MeV near the critical temperature T_c, Breit-Wigner
ansatz which can take into account the possible appearance of the thermal width
leads to the significant thermal width broadening of about 300 MeV with a
modest reduction of the peak center of about 100 MeV.
