  We describe the realization of the super Reshetikhin-Semenov-Tian-Shansky
(RS) algebra in quantum affine superalgebras, thus generalizing the approach of
Frenkel-Reshetikhin to the supersymmetric (and twisted) case. The algebraic
homomorphism between the super RS algebra and the Drinfeld current realization
of quantum affine superalgebras is established by using the Gauss decomposition
technique of Ding-Frenkel. As an application, we obtain Drinfeld realization of
quantum affine superalgebra $U_q[osp(1|2)^{(1)}]$ and its degeneration --
central extended super Yangian double $DY_\hbar[osp(1|2)^{(1)}]$.
