[en] New experimental data on the A-dependence of the yield of proton photoproduction on nuclei in cumulative as well as non-cumulative regions are presented. It is shown that if the reaction yield has the form f approximately Asup(n) the exponent n is the slowly varying function of the proton kinetic energy without any peculiarities observed in the case of π-meson photoproduction. The dependences n on the proton detection angle and primary γ-quantum energy in the interval (Esub(γ))sub(max) 0.25-4.5 GeV are presented as well