Abstract
The quantum Gelfand-Levitan equations for the nonlinear Schrödinger model of spin-½ particles are obtained. Two Izergin-Korepin relations are used in the derivation. A new type commutation relation of L operators is introduced to get the commutation relations which are needed for the study of S matrices and Green's functions. As examples, the four-point Green's functions and the two-body S matrices are given.