- The cross section for photoproduction of charmed hadrons from protons is studied using an effective Lagrangian that includes heavy charmed mesons and baryons. Both two-body final states involving c and charmed meson as well as three-body final states involving nucleon and charm-anticharm meson pair are included. An overall form factor is introduced in each process to take into account finite hadron sizes without breaking the gauge invariance. Using coupling constants determined either empirically or via SU(4) relations, we adjust the cutoff parameter in the form factor to reproduce measured total charmed hadron production cross section from photon-proton reactions at center-of-mass energy of 6 GeV. The resulting relative contribution from two-body and three-body final states is consistent with experiments. The predicted cross section for photoproduction of charmed hadron from protons near threshold is seen to be appreciable. The result is further compared with predictions from leading-order perturbative QCD. 2003 Elsevier B.V. All rights reserved.