  In the context of the left-right twin Higgs (LRTH) model, we first examine
the effects on the $Zt\bar t$ production at the ILC and LHC. Our results show
that the cross-sections can be significantly deviated from the standard model
predictions and thus provide a good probe for the LRTH model. We also estimate
the new production channel, $Zt\bar T $ or $Z\bar t T $ production, at the LHC.
Compared with $Zt \bar t$ production, we find that the $Z t \bar T$ production
can have a sizable production rate when the scale $f$ is not too high.
Considering the dominant decay mode $T\rightarrow \phi^{+}b\rightarrow tb\bar
b$, we find that $Z t\bar T $ final state has less background than $Zt\bar t$
production and may likely be observable at the LHC.
