  Rare decay process of the Higgs boson into a pair of $J/\Psi$ and $\Upsilon$
particles is studied within perturbative Standard Model and relativistic quark
model. The relativistic corrections connected with the relative motion of
quarks are calculated in the production amplitude and the wave functions of the
bound states. Numerical values of the decay widths of the Higgs boson are
obtained, which can be used for comparison with experimental data.
