  We study the effects of top-Higgs anomalous coupling in the production of a
pair of Higgs boson via gluon fusion at the Large Hadron Collider (LHC). The
introduction of anomalous $ttH$ coupling can alter the hadronic double Higgs
boson cross section and can lead to characteristic changes in certain kinematic
distributions. We perform a global analysis based on available LHC data on the
Higgs to constrain the parameters of $ttH$ anomalous coupling. Possible overlap
of the predictions due to anomalous $ttH$ coupling with those due to anomalous
trilinear Higgs coupling is also studied. We briefly discuss the effect of the
anomalous $ttH$ coupling on the $HZ$ production via gluon fusion which is one
of the main backgrounds in the $HH \to \gamma\gamma b {\bar b}$ channel.
