  The $b \rightarrow s l^+ l^-$ process is studied in the minimal supergravity
model in detail. Taking account of the long distance contributions from the
$c\overline{c}$ resonances, we calculate the branching ratio and the lepton
forward-backward asymmetry in this model. We find that there is a strong
correlation between the branching ratios of $b \rightarrow s \gamma$ and $b
\rightarrow s l^+ l^-$ processes and that the interference effect can change
the $b \rightarrow s l^+ l^-$ branching ratio in the off-resonance regions by
up to $\pm 15%$ depending on the relative phase between the long and short
distance contributions. Using various phenomenological constraints including
the branching ratio of $b \rightarrow s \gamma$, we show that there are regions
in the parameter space where the branching ratio of $b \rightarrow s l^+ l^-$
is enhanced by about 50% compared to the SM. We also show that the branching
ratio of $b \rightarrow s \nu{\overline \nu}$ is reduced at most by 10% from
the SM prediction.
