  We study the 2-flavor Nambu--Jona-Lasinio (NJL) model at finite temperature,
$T$, and chemical potential, $\mu$, in the dimensional regularization. The pion
and sigma meson masses are calculated at finite $T$ and $\mu$. The color
superconductivity is also discussed in the extended NJL model. We obtain the
phase structure of the chiral and color symmetry in the dimensional
regularization and compare the results with ones obtained in the cut-off
regularization.
