  We studied the photoproduction of $\psi^{\prime}$ in the forward regions in
polarized $\gamma p$ collisions at relevant HERA energies. We found that this
reaction is very effective to test the color-octet mechanism which is based on
the NRQCD factorization formalism. Furthermore we found that the value of the
NRQCD matrix elements can be severely constrained by measuring the two-spin
asymmetry, though the process depends on the polarized gluon distribution
$\Delta g(x)$.
