  We investigate quantum phase transitions of the two-dimensional S=1
Shastry-Sutherland model, which is characterized by the frustrated
orthogonal-dimer structure, by means of the exact diagonalization method and
the Ising-type series expansion method. We clarify how distinct spin gap phases
realized in the chain system are adiabatically connected to those in the
two-dimensional Shastry-Sutherland model. The effect of single-ion anisotropy
is also discussed.
