  We perform numerical simulations to study the secular orbital evolution and
dynamical structure in the quintuplet planetary system 55 Cancri with the
self-consistent orbital solutions by Fischer and coworkers (2008). In the
simulations, we show that this system can be stable at least for $10^{8}$ yr.
In addition, we extensively investigate the planetary configuration of four
outer companions with one terrestrial planet in the wide region of 0.790 AU
$\leq a \leq $ 5.900 AU to examine the existence of potential asteroid
structure and Habitable Zones (HZs). We show that there are unstable regions
for the orbits about 4:1, 3:1 and 5:2 mean motion resonances (MMRs) with the
outermost planet in the system, and several stable orbits can remain at 3:2 and
1:1 MMRs, which is resemblance to the asteroidal belt in solar system. In a
dynamical point, the proper candidate HZs for the existence of more potential
terrestrial planets reside in the wide area between 1.0 AU and 2.3 AU for
relatively low eccentricities.
