  The entanglement of two atoms is studied when the two atoms are coupled to a
single-mode thermal field with different couplings. The different couplings of
two atoms are in favor of entanglement preparation: it not only makes the case
of absence entanglement with same coupling appear entanglement, but also
enhances the entanglement with the increasing of the relative difference of two
couplings. We also show that the diversity of coupling can improved the
critical temperature. If the optical cavity is leaky during the time evolution,
the dissipative thermal environment is benefit to produce the entanglement.
