  The phase structure of Nambu-Jona-Lasinio model with N-component fermions in
curved space-time is studied in the leading order of the 1/N expansion.
  The effective potential for composite operator $\bar{\psi}\psi$ is calculated
by using the normal coordinate expansion in the Schwinger proper-time method.
  The existence of the first-order phase transition caused by the change of the
space-time curvature is confirmed and the dynamical mass of the fermion is
calculated as a simultaneous function of the curvature and the four-fermion
coupling constant.
  The phase diagram in the curvature and the coupling constant is obtained.
