  We suggest a new left-right symmetric grand unified model by extending
Pati-Salam group to contain an isospin SU(2) and a flavor SO(3) subgroup, where
the superheavy fermions are introduced as a mirror to the low-energy standard
model fermions. The model undergoes three steps to break to the SM by means of
the specified Higgs multiplets. The model few parameters can elegantly
accommodate whole mass spectra for all the particles at the electroweak scale,
especially, two different flavor mixing for the quark and lepton sectors are
reproduced in agreement with the current experimental data very well. The
strong CP violation is excellently explained. The matter-antimatter asymmetry
in the universe is successfully implemented through the B-L violating decays of
the superheavy gauge bosons. The model also predicts that the lightest
right-handed Majorana neutrino, whose mass is about several hundred GeVs and
energy is about $10^{16}$ GeV, is possibly a candidate for the dark matter.
