  We show that $\phi$ radiative decays into scalar mesons [$f_0$(975),
$a_0$(980)$\equiv S$] can provide important clues on the internal structures of
these mesons. Radiative decay widths vary widely: $B.R.=10^{-4}-10^{-6}$
depending on the substructures ($q\bar q$, $qq\bar q\bar q$, $K\bar K$,
glueball). Hence, we could discriminate among various models by measuring these
widths at future $\phi$ factories. The understanding of these meson structures
is valuable not only in hadron spectroscopy but also in nuclear physics in
connection with the widely-used but little-understood $\sigma$ meson. We also
find that the decay $\phi\rightarrow S\gamma \rightarrow K^0 \bar K^0\gamma$ is
not strong enough to pose a significant background problem for studying CP
violation via $\phi\rightarrow K^0 \bar K^0$ at the $\phi$ factories.
