  We discuss a mechanism which can reduce the S and T parameters in dynamical
electroweak symmetry breaking scenario. It is interesting that not only T but
also S parameters can be made small even if large isospin violation exists,
which can realize the heavy top quark. The point is that if massive vector-like
fermions, which have gauge invariant masses, can condense and break the
electroweak symmetry, the S and T parameters can be small because of the
decoupling theorem. Moreover, the model predicts a heavier Higgs boson, which
may be found in LHC. The presentation basically follows the original papers.
