  The extension of the standard model with pairs of the vector-like families is
studied. The quark mixing matrices for the left- and right-handed charged
currents, as well as those for the flavour changing neutral currents, the Z and
Higgs mediated, are found. Both the model independent parametrization for an
arbitrary case and an explicit realization for the case with one pair of the
heavy vector-like families are presented. The extension opens new prospects for
studying deviations from the standard model in the future experiments at high
energies.
