  The cutoff scheme dependence in the several formulations of the Exact
Renormalization Group (ERG) is investigated. It is shown that the cutoff scheme
dependence of the Wilsonian effective action is regarded as a certain
coordinate transformation on the theory space. From this observation the
Wilsonian effective actions are found to suffer from strong dependence on the
schemes even in the infra-red asymptotic region for massive theories. However
there is no such scheme dependence in the one particle irreducible parts of
them, which is called the effective average actions. We also derive the
explicit form of the Polchinski RG equation in the sharp cutoff limit. Finally
this equation is shown to be identical with the Wegner-Houghton RG equation.
