  We construct an induced gravity (pregeometry) where both the Newton constant
and the cosmological constant appear as integration constants in solving field
equations. By adding the kinetic terms of ghosts and antighosts, an action of
the induced gravity is transformed to a topological field theory. Moreover, by
solving field equations of the topological field theory in the FRW universe, we
find an inflation solution. The present study might shed some light on a close
relationship between the induced gravity and the topological quantum field
theory.
