  In this paper, the quark distribution amplitudes of 1S and 2S heavy
quarkonium states are studied in terms of Gaussian-type wave functions. The
transverse momenta $p_\perp$ integrals of the formulae for the decay constant
are performed analytically. Then the quark distribution amplitudes are
obtained. In addition, the $\xi$-moments are also calculated. After fixing the
relevant parameters appearing in the quark distribution amplitude, the curves
of the quark distribution amplitude for 1S and 2S heavy quarkonium states are
plotted. Finally, the numerical results of this approach are compared with the
other theoretical predictions.
