  It is suggested that various hierarchy problems in supersymmetric standard
model, i.e. the Yukawa hierarchies, the \mu problem, and the suppression of
dangerous baryon and/or lepton number (B/L) violating couplings, are resolved
altogether in the framework of horizontal U(1) symmetry whose spontaneous
breaking results in the appearance of one expansion parameter (the Cabibbo
angle). Within a reasonable range of U(1) charges, there exist a few models
compatible with experiments. The specific sizes of B/L violating couplings of
these models are calculated and several phenomenological consequences are
discussed.
