  We study the glueball properties at finite temperature below T_c using SU(3)
anisotropic quenched lattice QCD with beta=6.25, the renormalized anisotropy
gamma = a_s/a_t = 4 and 20^3 \times N_t (N_t = 35, 36, 37, 38, 40, 43, 45, 50,
72). From the temporal correlation analysis with the smearing method, we
observe the mass reduction of about 20 % for the lowest 0^{++} glueball as
m_G(T) = 1.25 \pm 0.1 GeV for 0.8 T_c < T < T_c in comparison with m_G \simeq
1.5 \sim 1.7 GeV at T \sim 0.
