  The WHOT-QCD Collaboration is pushing forward lattice studies of QCD at
finite temperatures and densities using improved Wilson quarks. We first
present results on QCD at zero and finite densities with two flavors of
degenerate quarks (N_F=2 QCD) adopting the conventional fixed-Nt approach. We
then report on the status of a study of N_F=2+1 QCD adopting a fixed-scale
approach armed with the T-integration method which we have developed.
