  We consider a scenario where the top-quark mass is generated dynamically, and
study the implication of the present experimental values for $m_t$ and the $T$
parameter. We assume technicolor-like scenario for inducing the $W$ mass and an
effective four fermi operator for inducing the top-quark mass. We also assume
that only this four fermi operator is relevant at low energy. Then we estimate
in detail the strength $G$ and the intrinsic mass scale $M$ of the four fermi
operator. Unitarity bound is used to quantify the strength of $G$. We find that
$G/4\pi \sim {\cal O}(1)$ and that $M$ is of the order of $\Lambda_{TC} \simeq
1 \sim 2$~TeV or less. Namely the four fermi operator cannot be treated as
`point-like' around the electroweak scale. Furthermore we estimate the
contribution of the four fermi operator to the $T$ parameter. We find that the
QCD correction to the top-quark mass function reduces the contribution to the
$T$ parameter by about 40\%. By comparing the results with the present
experimental bound, we obtain another upper bound on $M$ which is typically in
several to 10~TeV region.
