  We present results of a recent work on the reaction mechanism of $\eta n$
photoproduction off the neutron in the range of $ \sqrt{s} \approx 1.5 - 1.9$
GeV and discuss the role of various nucleon resonances listed in the Particle
Data Group (PDG). We make use of an effective Lagrangian approach combining
with a Regge method. The total and helicity-dependent cross sections
$\sigma_{1/2},\,\sigma_{3/2}$ are computed and the numerical results are in
good agreement with the A2 experimental data.
