  We calculate the contributions of the flavor changing scalar ($FCS$)
couplings arised from topcolor-assisted technicolor ($TC2$) models at
tree-level to the $t\gamma$ and $tZ$ production at the Tevatron and $LHC$
experiments. We find that the production cross sections are very small at the
Tevatron with $\sqrt{s}=1.96TeV$, which is smaller than 5 fb in most of the
parameter space of $TC2$ models. However, the virtual effects of the $FCS$
couplings on the $t\gamma(Z)$ production can be easily detected at the $LHC$
with $\sqrt{s}=14TeV$ via the final state $\gamma l\bar{\nu}b$
($l^{+}l^{-}l\bar{\nu}b$).
