  Non-perturbative renormalization group approach suggests that a large class
of nonlinear sigma models are renormalizable in three dimensional space-time,
while they are non-renormalizable in perturbation theory. ${\cal N}=2$
supersymmetric nonlinear sigma models whose target spaces are
Einstein-K\"{a}hler manifolds with positive scalar curvature belongs to this
class. hermitian symmetric spaces, being homogeneous, are specially simple
examples of these manifolds. To find an independent evidence of the
nonperturbative renormalizability of these models, the large N method, another
nonperturbative method, is applied to 3-dimensional ${\cal N}=2$ supersymmetric
nonlinear sigma models on the target spaces $CP^{N-1}=SU(N)/[SU(N-1)\times
U(1)]$ and $Q^{N-2}=SO(N)/[SO(N-2)\times SO(2)]$, two typical examples of
hermitian symmetric spaces.
  We find that $\beta$ functions in these models agree with the results of the
nonperturbative renormalization group approach in the next-to-leading order of
1/N expansion, and have non-trivial UV fixed points. The $\beta$ function of
the $Q^{N-2}$ model receives a nonzero correction in the next-to-leading order
of the 1/N expansion.
  We also investigate the phase structures of our models. The $CP^{N-1}$ model
has two phases; SU(N) symmetric and asymmetric phase. The $Q^{N-2}$ model has
three phases; Chern-Simons, Higgs and SO(N) broken phases. In the Chern-Simons
and Higgs phase, SO(N) symmetry remains unbroken and all dynamical fields
becomes massive. An auxiliary gauge field also acquires mass, through an
induced Chern-Simons term in the Chern-Simons phase, and through the vacuum
expectation value of a di-quark bound state in the Higgs phase.
