  Supersymmetric (SUSY) standard models in which the lightest SUSY particle
(LSP) is an ultralight gravitino (m_{3/2}=O(1) eV) are very attractive, since
they are free from the cosmological gravitino problems. If the neutralino is
the next lightest SUSY particle (NLSP), it decays into a photon and the
gravitino in collider experiments. We propose a simple test for the lightness
of gravitino at the LHC.
