  By use of single instanton approximation the twist-3 light-cone distribution
amplitudes of pion as well as the p-wave mesons, i.e., $f_{0}(1370)$,
$K_{0}^{\ast}(1430)$ and $a_{0}(1450)$ are investigated within the framework of
QCD moment sum rules with inclusion of instanton effects based on the valence
quark model. Results show that there is much change on light-cone distribution
amplitudes by the isospin- and chirality-dependent instanton contribution
compared with the instanton-free ones. We find the intanton involved twist-3
LCDAs are non-positive-definite within some range of momentum fraction and
there are rapid changes at two ends of momentum fraction. To guarantee the
convergence of moments by the method in this work a low instanton density
should be adopted, for instance $n_{c}=1/2\rm{fm^{-4}}$ is welcomed. Possible
ingredients which might have impact on the results are briefly discussed. These
light-cone distribution amplitudes may be helpful to analyze exclusive heavy
flavored processes.
