  The chiral phase transition of the finite temperature QCD is discussed in the
ladder approximated Exact (Wilson's) Renormalization Group (ERG). The gluon
thermal mass is incorporated by the Hard Thermal Loop (HTL) approximation. We
calculated a critical temperature $T_c$, a critical exponent $\nu$, and order
parameters such as chiral condensate $<\bar{\psi}\psi>$ and pion decay
constants with this approximation. The dependences of the pion decay constants
on an unphysical parameter are fairly improved by including contributions from
momentum dependent vertices. The critical temperature was found as: $T_c\approx
124$ MeV for 3-flavors. It was shown that the critical temperature considerably
depends on the approximation scheme for the gluon thermal mass term. We also
calculated the temperature dependence of the chiral condensate, $\pi$ decay
constants, and the pion velocity.
