  We study coherent photoproduction of $\psi'$ and the subsequent suppression
in high energy nuclear collisions. The hot medium effect on charmonium
photoproduction is controlled by the competition between the fireball size and
nuclear size. When the former is smaller than the later, the photoproduction is
only slightly affected by the hot medium. We calculate the yield ratio of
$\psi'$ to $J/\psi$ in semi-central Pb-Pb collisions at LHC energy, while the
high $p_T$ limit is characterized by the fireball, its value in low $p_T$ limit
can still reach the significant enhancement by photoproduction.
