  The analytic forms of the asymptotic quasinormal frequencies of a coupled
scalar field in the Garfinkle-Horowitz-Strominger dilaton spacetime is
investigated by using the monodromy technique proposed by Motl and Neitzke. It
is found that the asymptotic quasinormal frequencies depend not only on the
structure parameters of the background spacetime, but also on the coupling
between the scalar fields and gravitational field. Moreover, our results show
that only in the minimal couple case, i.e., $\xi$ tends zero, the real parts of
the asymptotic quasinormal frequencies agrees with the Hod's conjecture,
$T_H\ln{3}$.
