  $\eta \rightarrow \pi^{0} \gamma \gamma$ and $\ggpipi$ are considered in
$O(p^{6})$ chiral perturbation theory. In addition to the usual $\rho,\omega$
contributions, there are two $O(p^{6})$ operators (${\cal L}_{6,m}$) arising
from explicit chiral symmetry breaking. Since only one of the two operators
contributes to $\etapigg$, the coefficient of this operator ($\equiv d_3$) can
be determined in two ways : (i) from the measured decay rate of $\eta
\rightarrow \pi^{0} \gamma \gamma$, and (ii) by assuming the resonance
saturations of the low energy coefficients in the $O(p^{6})$ chiral lagrangian.
We find that two methods lead to vastly different values of $d_3$, which would
indicate that either the measured decay rate for $\eta \rightarrow \pi^{0}
\gamma \gamma$ is too large by a factor of $2 \sim 3$, or the resonance
saturation assumptions do not work for $d_3$.
