  We study a multiply warped products manifold associated with the
Reissner-Nordstrom metric to investigate the physical properties inside the
black hole event horizons. It is shown that, different from the uncharged
Schwarzschild metric, the Ricci curvature components inside the
Reissner-Nordstrom black hole horizons are nonvanishing, while the Einstein
scalar curvature vanishes even in the interior of the charged metric.
Introducing a perfect fluid inside the Reissor-Nordstrom black hole, it is also
shown that the charge plays effective roles of decreasing the mass-energy
density and the pressure of the fluid inside the black hole.
