  A global analysis is performed using the latest data from LEP and SLC.
Constraints on the electroweak universal parameters ($S,T,U$) and on the masses
of the top quark and Higgs boson within the Standard Model (SM) are
investigated. The uncertainties due to the QCD and QED effective couplings,
$\alpha_s(\mz)$ and $\bar{\alpha}(\mmz)$, are examined in detail. Even though
the mean value of $S$ is increased to be consistent with zero, the naive
Technicolor models are still disfavored due to its reduced error. Within the
SM, we find the 90\,\%CL constraints; $133\gev<m_t<190\gev$ and
$10\gev<\mh<440\gev$ for $\alpha_s(\mz)=0.116$ and $1/\bar{\alpha}(\mmz)
=128.72$. The experimental constraints on the $\zbb$ vertex form-factor,
$\delb(\mmz)$, play an important role in disfavoring the region of large
$m_t(m_t \sim 200\gev)$ and large $\mh(\mh \sim 1000\gev)$. If $m_t$ is
precisely known, the present electroweak data give a rather strict upper bound
on the Higgs mass, $\mh<140\,(300)\gev\,$ at 95\%~CL, for $m_t=160\, (175)\gev$
and for the above $\alpha_s(\mz)$ and $\bar{\alpha}(\mmz)$.
