[en] We investigate the influence of the Higgs scalars in the SO(10) grand unified model. Special emphasis is laid on whether or not we can construct the SO(10) model having light SU(2)sub(R) weak bosons and the proton decays. Inclusion of a few antisymmetric 5 rank (126) tensors makes us possible to lower the grand unification mass scale down to O(10¹⁴ GeV) and to have the SU(2)sub(L) x SU(2)sub(R) x U(1)sub(B-L) electroweak symmetry restored around (100 -- 300) GeV with the reasonable values of αsub(s) and sin²theta sub(w). Furthermore, we can implement the extended color SU(4) symmetry around the mass scale 10¹¹ GeV. (author)