  We investigate the problem of derivation of consistent equations of motion
for the massive spin 2 field interacting with gravity within both field theory
and string theory. In field theory we derive the most general classical action
with non-minimal couplings in arbitrary spacetime dimension, find the most
general gravitational background on which this action describes a consistent
theory and generalize the analysis for the coupling with background scalar
dilaton field. We show also that massive spin 2 field allows in principle
consistent description in arbitrary background if one builds its action in the
form of an infinite series in the inverse mass square. Using sigma-model
description of string theory in background fields we obtain in the lowest order
in $\alpha'$ the explicit form of effective equations of motion for the massive
spin 2 field interacting with gravity from the requirement of quantum Weyl
invariance and demonstrate that they coincide with the general form of
consistent equations derived in field theory.
