  In order to construct a massive tensor theory with a smooth massless limit,
we apply two kinds of gauge-fixing procedures, Nakanishi's one and the BRS one,
to two models of massive tensor field. The first is of the Fierz-Pauli (FP)
type, which describes a pure massive tensor field; the other is of the
additional-scalar-ghost (ASG) type, which includes a scalar ghost in addition
to an ordinary tensor field. It is shown that Nakanishi's procedure can
eliminate massless singularities in both two models, while the BRS procedure
regularizes the ASG model only. The BRS-regularized ASG model is most promising
in constructing a complete nonlinear theory.
