  We perform a detailed study of the inclusive branching ratio and the
forward-backward asymmetry of the rare B decay process $B \longrightarrow X_{s}
\tau^{+} \tau^{-}$ in the flipped SU(5) model, a predictive model which has
only two free parameters, plus the sign of the higgs mixing mass $\mu$, to
describe mass spectrum and mixings of about 30 sparticles. In contrast to other
works dealing with such a topic, our study has included the contributions of
the neutral higgs bosons through penguin diagrams to this process under the
context of supersymmetry. In some regions of the parameter space, due to the
substantial enhancement effects coming from supersymmetry, these contributions
become quite significant and could make the flavor change process $B
\longrightarrow X_{s} \tau^{+} \tau^{-}$ a microscope to probe the regions of
large tan$\beta$ and a window to gain an insight into new physics beyond the
standard model(SM).
