  In this talk, we introduce a new scenario of grand unified theory (GUT) with
anomalous $U(1)_A$ gauge symmetry. Since generic interactions (including
non-renormalizable interactions) are introduced, once we fix the symmetry of
the theory, we can define the theory without O(1) coefficients. The number of
parameters to determine the symmetry is just 11 or 12 integer parameters which
are anomalous $U(1)_A$ charges(integer) for introduced multiplets. It is
surprising that the GUT scenario can explain doublet-triplet splitting, quark
and lepton masses and mixing angles. In neutrino sector, the scenario realizes
LMA solution for solar neutrino problem and large $U_{e3}=O(0.1)$. Moreover,
the scenario predicts that the unification scale becomes smaller than the usual
GUT scale, namely proton decay via dimension 6 operators may be seen in future
experiments. This talk is based on the
papers\cite{maekawa,maekawa2,maekawa3,BM,MY}.
