  We study radiative corrections on $Zb{\bar b}$ vertex generated by the ETC
gauge bosons, ``diagonal'' as well as sideways. Although the oblique
corrections due to the ETC bosons are small in comparison with the oblique
correction due to the technicolor dynamics, the non-oblique corrections result
in substantial shift of contour plot in the $S$-$T$ plane. We show that such a
shift due to the non-oblique corrections is actually important for discussing
$S$ and $T$ values in the technicolor models.
