  The effect of the shock propagation on neutrino oscillation in supernova is
studied paying attention to evolution of average energy of $\nu_{e}$ and
$\bar{\nu}_{e}$. We show that the effect appears as a decrease in average
$\nu_{e}$ (in case of inverted mass hierarchy, $\bar{\nu}_{e}$) energy at
stellar surface as the shock propagates. It is found that the effect is
significant 2 seconds after bounce if $3 \times 10^{-5} < \sin^{2}{\theta_{13}}
< 10^{-2}$.
