Taking the intrinsic decoherence effect into account,this paper investigates the entanglement of a two-qubit anisotropic Heisenberg XY Z model in the presence of nonuniform exteal magnetic fields by employing the concurrence as entanglement measure.It is found that both the intrinsic decoherence and the anisotropy of the system give a significant suppression to the entanglement.Moreover it finds that the initial state of the system plays an important role in the time evolution of the entanglement,which means that the entanglement of the system is independent of the nonuniformity and uniformity of the magnetic field when the system is in the initial state |ψ(0)>=|00>and |ψ(0)>=m |01＞+n|10＞,respectively.