  As a top quark factory, the LHC can test the new physics models used to
explain the top quark forward-backward asymmetry A^t_FB measured at the
Tevatron. In this work we perform a comparative study for two such models: the
W'-model and the color triplet diquark (\phi) model. Requiring these models to
explain A^t_FB and also satisfy the top pair production rate measured at the
Tevatron, we examine their contributions to the LHC observables such as the
polarization and charge asymmetry in top quark and W' (or \phi) productions. We
find that these observables can be enhanced to the observable level and the
current LHC measurement on the top charge asymmetry can already tightly
constrain the W'-model. We also find that each observable shows different
characteristics in different models, which can be utilized to discriminate the
models.
