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The shape transition between the vibrational U (5) and deformedγ-unstable O(6) dynamical symmetries of sd interacting boson model has been investigated by con-sidering a modified O(6) Hamiltonian, providing that the coefficients of the Casimir operator of O(5) are N-depen-dent, where N is the total number of bosons. The modified O(6) Hamiltonian does not contain the number operator of the d boson, which is responsible for the vibrational motions. In addition, the deformation features can be achieved without using the SU(3) limit by adding to the O (6) dynamical symmetry the three-body interaction [QQQ](0), where Q is the O(6) symmetric quadrupole operator. Moreover, triaxiality can be generated through the inclusion of the cubic d-boson interactiond [d?d?d?](3)·[d～d～d～](3). The classical limit of the potential energy surface (PES), which represents the expected value of the total Hamiltonian in a coherent state, is studied and examined. The modified O(6) model is applied to the even–even 124-132Xe isotopes. The parameters for the Hamilto-nian and the PESs are calculated using a simulated search program to obtain the minimum root mean square deviation between the calculated and experimental excitation ener-gies and B(E2) values for a number of low-lying levels. Agood agreement between the calculations and experiment results is found.