  In this paper, we extend the generalization of Drinfeld realization of
quantum affine algebras to quantum affine superalgebras with its Drinfeld
comultiplication and its Hopf algebra structure, which depends on a function
$g(z)$ satisfying the relation: $g(z)=g(z^{-1})^{-1}.$ In particular, we
present the Drinfeld realization of $U_q(\hat {\frak osp}(1,2))$ and its Serre
relations.
