  The late-time evolution of the charged massive Dirac fields in the background
of a Reissner-Norstr\"om (RN) black hole is studied. It is found that the
intermediate late-time behavior is dominated by an inverse power-law decaying
tail without any oscillation in which the dumping exponent depends not only on
the multiple number of the wave mode but also on the field parameters. It is
also found that, at very late times, the oscillatory tail has the decay rate of
$t^{-5/6}$ and the oscillation of the tail has the period $2\pi/\mu$ which is
modulated by two types of long-term phase shifts.
