  In this paper, we are concerned with the asymptotic behavior of the
Neumann-Poincare operator for Helmholtz system. By analyzing the asymptotic
behavior of spherical Bessel function near the origin and/or approach higher
order, we prove the asymptotic behavior of spectral of Neumann-Poincare
operator when frequency is small enough and/or the order is large enough. The
results show that spectral of Neumann-Poincare operator is continuous at the
origin and converges to zero from the complex plane in general.
