  Gravitino is one feasible candidate for the dark matter in supergravity
models. With its couplings being suppressed by the Plank mass, gravitino
interacts very weakly with other particles, making its direct detection, or
production at colliders practically impossible. The signatures of this scenario
mainly arise from the next lightest supersymmetric particle (NLSP) which is
metastable due to the very weak coupling. There are many possibilities for the
NLSP, and here I will review the feasibility of stop particle as the NLSP and
discuss its phenomenology.
