  High resolution simulations reveal that in the cold dark matter scenario the
structures form hierarchically and a large number of substructures survive in
the galactic halos. The substructures can be probed if they emit gamma rays via
dark matter annihilation. We calculated the gamma ray fluxes from the dark
matter annihilations in the substructures of our Galaxy within the frame of the
minimal supersymmetric extension of the standard model. The uncertainties of
the prediction from both the low energy supersymmetry and especially from the
density profiles of dark matter in the substructures are carefully
investigated. The cumulative number of substructures emitting gamma rays above
any given flux is calculated. Detectability of the gamma rays from the
substructures is discussed. We propose the viability to detect these signals
through the ground large field of view detectors.
