  In strongly coupled supersymmetric SO(N_c) gauge theories with N_f-quarks for
N_c-2<=N_f(<=3(N_c-2)/2), their low-energy physics can be described by
Nambu-Goldstone superfields associated with dynamical flavor symmetry breaking,
which should be compared with the absence of flavor symmetry breaking in the
conventional description in terms of magnetic degrees of freedom. The presence
of the flavor symmetry breaking is confirmed by the well-known instanton
effects in SO(N_c) with N_f=N_c-2, which are also described by our proposed
effective superpotential. For N_f>=N_c-1, our effective superpotentials utilize
baryonic configurations as well as mesons composed of two quarks. The baryonic
configurations are supplied by "diquarks" made of N_c-1 quarks for N_f=N_c-1
and by baryons composed of N_c quarks for N_c>=N_f. It is argued that our
effective superpotentials exhibit the holomorphic decoupling property, the
anomaly-matching property and correct description of instanton effects in
SO(N_c) when N_f-N_c+2 quarks become massive if N_f>=N_c-1.
