In quantum mechanics,the evolution of a quantum state is a unitary evolution,the evolution process can be described by an action of a unitary operator on the quantum state and the process is time reversible.Based on this fundamental fact,Gerard t Hooft has introduced the concept of equivalence classes of quantum states and described the unitary evolutions of quantum states by unitary transformation between two equivalence classes.In the present paper,we will use the concept of equivalence classes and their transformations to construct universal quantum logic gates in the quantum information theory and give their generalized forms.In the end of this paper we will show that these quantum logic gates can be realized by some intrinsic interaction Hamiltonian of the system.