  The renormalization group equations (RGEs) of the mass matrices of quarks and
leptons in a SO(10) model with two Higgs scalars in the Yukawa coupling are
studied. This model is the minimal model of SUSY and non-SUSY SO(10) GUT which
can reproduce all the experimental data. Non-SUSY SO(10) GUT model has the
intermediate energy phase, Pati-Salam phase, and passes through the symmetry
breaking pattern, $SO(10) \to SU(2)_L \times SU(2)_R \times SU(4)_C \to SU(2)_L
\times U(1)_Y \times SU(3)_C$. Though minimal, it has, after the Pati-Salam
phase, four Higgs doublets in Yukawa interactions. We consider the RGE's of the
Yukawa coupling constants of quarks and charged leptons and of the coupling
constants of the dimension five operators of neutrinos corresponding to the
above symmetry breaking pattern. The scalar quartic interactions are also
incorporated.
