  We develop the formal tools needed to construct helicity amplitudes for
massive gravitino in N=1 SUGRA. We start by considering the helicity states for
massive spin-3/2 particles, which involves the solutions of Rarita-Schwinger
equation. These solutions are written in terms of the helicity bra-ket notation
and are used then to derive the interactions of gravitino with matter and gauge
supermultiplets within N=1 Supergravity. The corresponding interactions of
goldstinos are discussed too, relying on the goldstino-gravitino equivalence
theorem. Finally to appreciate the power of our methods we evaluate the decay
width chi_0 -> \gamma G, as well as the cross sections for e^+ e- -> GG.
