  We review recent progress in lattice QCD at finite density. The phase diagram
of QCD and the equation of state at finite temperature and density are
discussed. In particular, we focus on the critical point terminating a first
order phase transition line in the high density region. The critical point is
one of the most interesting features that may be discovered in heavy-ion
collision experiments. We summarize the current discussion on the existence of
a critical point in the QCD phase diagram and discuss some attempts to find the
critical point by numerical simulations.
