  We study the quantum conserved charges and S-matrices of N=2 supersymmetric
sine-Gordon theory in the framework of perturbation theory formulated in N=2
superspace. The quantum affine algebras ${\widehat {sl_{q}(2)}}$ and super
topological charges play important roles in determining the N=2 soliton
structure and S-matrices of soliton-(anti)soliton as well as soliton-breather
scattering.
