  Motivated by the possibility that the right-handed top-quark (t_R) is
composite, we discuss the effects of dimension-six operators on the Higgs boson
production at the LHC. When t_R is the only composite particle among the
Standard Model (SM) particles, the (V+A)\otimes (V+A) type four-top-quark
contact interaction is expected to have the largest coefficient among the
dimension-six operators, according to the Naive Dimensional Analysis (NDA). We
find that, to lowest order in QCD and other SM interactions, the cross section
of the SM Higgs boson production via gluon fusion does not receive corrections
from one insertion of the new contact interaction vertex. We also discuss the
effects of other dimension-six operators whose coefficients are expected to be
the second and the third largest from NDA. We find that the operator which
consists of two t_R's and two SM Higgs boson doublets can recognizably change
the Higgs boson production cross section from the SM prediction if the cut-off
scale is \sim 1TeV.
