The intertwining method has been applied to the effective potential of the spin Hamiltonian H = -gamma S-z(2) - BSx. The supersymmetric partner potentials, some of which are singular, are obtained by using low-lying states of this potential. Applying the intertwining method successively, hierarchy of effective potentials has been established. Supersymmetric partner of the transformed spin Hamiltonian's effective potential has also been constructed. (c) 2005 Elsevier B.V. All rights reserved.