  We investigate quantum kinetic theory for a massive fermion system under a
rotational field. From the Dirac equation in curved space we derive the
complete set of kinetic equations for the spin components of the covariant and
equal-time Wigner functions. While the particles are no longer on a mass shell
in general case due to the rotation-spin coupling, there are always only two
independent components, which can be taken as the number and spin densities.
With the help from the off-shell constraint we obtain the closed transport
equations for the two independent components in classical limit and at quantum
level. The classical rotation-orbital coupling controls the dynamical evolution
of the number density, but the quantum rotation-spin coupling explicitly
changes the spin density.
