  A two-dimensional kagome lattice is theoretically investigated within a
simple tight-binding model, which includes the nearest neighbor hopping term
and the intrinsic spin-orbit interaction between the next nearest neighbors. By
using the topological winding properties of the spin-edge states on the
complex-energy Riemann surface, the spin Hall conductance is obtained to be
quantized as $-e/2\pi$ ($e/2\pi$) in insulating phases. This result keeps
consistent with the numerical linear-response calculation and the
\textbf{Z}$_{2}$ topological invariance analysis. When the sample boundaries
are connected in twist, by which two defects with $\pi$ flux are introduced, we
obtain the spin-charge separated solitons at 1/3 (or 2/3) filling.
